DOD vs. 802.11b

goombah99 writes "The NY times (reg required) reports that "The Defense Department, arguing that an increasingly popular form of wireless Internet access could interfere with military radar, is seeking new limits on the technology". It would seem they have a good point; radar is an essential for both defense and civilian aviation as well as ship navigation in tight quarters. Critics of the restrictions contend technology can limit the interference, but what proof is there to these assertions? Sure we all want wireless internet but maybe there should be more careful review of its consequences."

Comments

fear mongering

[dbrower]

it's not about current wifi, but about expansion into the 5ghz band being debated. there are no current examples of interference.

-dB

Re:fear mongering

[corebreech]

Fear mongering? No current examples of interference???

No current examples of interference are possible, since our military appears to be completely incompetent!

Consider 9/11. At approximately the same time the first airliner struck the World Trade Center, the flight that was to hit the Pentagon went NORDO, i.e., was identified as a hijacked aircraft. This thing was tracked on radar for FIFTY FUCKING MINUTES before crashing into THE FUCKING PENTAGON of all places and the fine men and women charged with protecting our airspace DID ABSOLUTELY NOTHING TO PREVENT IT!

It takes big balls on their part to now say that we can't do any further development on WiFi because it will impair the military use of radar. I fail to see how military radar can be rendered any more ineffective.

Re:fear mongering

[duffbeer703]

What were they supposed to do? Shoot the planes down and have them crash into a neighborhood?

Densely populated NYC suburbs extend out in a 75 mile or more radius. I suppose crashing fully loaded jets into schools and apartment buildings would have been an effective use of military power.

Re:fear mongering

[Catbeller]

The only person with the authority to give the order to shoot down a civilian airliner is the President, who was sitting in a classroom like a stunned sloth for a half hour instead of being a President. The military was competent. Bush was not.

If he had gotten up and actually acted, the planes would have been followed by fighter planes, and given authorization, shot down before they got close enough to take out the towers.

It wasn't the military's fault. Hell, I think they took out the flight over Pennsylvania -- the blast debris was too widely scattered for a crash.

Bush sat like a deer frozen in headlights instead of giving the order to shoot if necessary. Without his OK, there could be no shootdown.

Then he ran away. The story about the White House being under threat was later dismissed by the White House, to the utter disinterest of reporters.

If Clinton had failed to get out of that chair, and those planes had hit the buildings... if he had fled to Louisiana... he'd have impeached the next week. Trent Lott and all the other patriots who gave Bush their fawning support would have personally shot Clinton, if he had shown the stupidity and cowardice displayed by Bush.

Had to be said. The planes hit because the order was never give to shoot. The order wasn't given because Bush just sat there, listening to some children.

Re:fear mongering

[corebreech]

Here's the timeline.

8:20 Departs.
8:46 Goes off course.
9:41 Crashes into Pentagon.

YOU ARE FULL OF SHIT

Re:fear mongering

[corebreech]

No argument about Bush...

But no order was needed to put the planes in the air in the first place. They tracked Flight 77 for over forty minutes before even scrambling aircraft to intercept.

They can scramble to intercept without an order from the President.

If the military wasn't incompetent, then they were complicit.

Re:fear mongering

[eggboard]

It's beyond just the middle, unallocated 5 GHz range: the military is criticizing the lower and upper band U-NII allocations, too.

The headline on this article is wrong: it's 802.11a, not 802.11b, that operates in 5 GHz. I confirmed with the NY Times journalist that 5 GHz was the only band at question here.

Re:fear mongering

[saider]

Well said from the comfortable position of 1 year's worth of contemplation.

Re:fear mongering

[stinky wizzleteats]

If he had gotten up and actually acted, the planes would have been followed by fighter planes, and given authorization, shot down before they got close enough to take out the towers.

I notice your conspicuous use of the plural term "towers" above. Do you honestly mean to suggest that on the morning of 9/11, before the first tower was struck, it was appropriate and justifiable behavior to shoot down airliners that were flying off-course?

Let's take the discussion further. Let's move to just after the first plane crash. Do you expect the president of the United States to authorize the destruction of every airliner in U.S. airspace which is off-course because one happened to run into a building?

I don't know what a careful decision on the part of the Commander in Chief to use deadly force against innocent civilians looks like in your political universe, but I sleep better at night knowing that my president is reluctant to take such action.

Re:fear mongering

[finkployd]

Well geeze, where were you if you knew these four planes were being hijacked to ram into buildings? You should have been telling the military to shoot down any hijacked planes because unlike the vast majority of hijacked planes, you know these ones were going to use used in this way.
What a gift your forsight could have been, it is a shame our President did not have the gift you appearently did.

Finkployd

Re:fear mongering

[commodoresloat]

4 simultaneously hijacked planes sounds to me like a pretty compelling reason to improvise.

Re:fear mongering

[stinky wizzleteats]

Is it just me, or is there a rash of unfair moderation lately? Can anyone explain the moderation on the parent post in terms other than "you pissed off the moderator and they don't agree with you"?

What's going on? Are there just more idiots in the queue these days, or have we all slacked off on M2ing?

Re:fear mongering

[dj2fast]

I have a little something to add to this debate, I am familiar with radars due to my career in the air national guard and avionics. current wi-fi technology would not interfere at all with aircraft radar because 99 percent of them TX on X-band (9ghz) as for ground radars, like the tps-75 AC&W radar, I can guarantee wi-fi would not interfere. because we employ anti jamming countermeasures that would easily overcome any fixed frequency device

Re:fear mongering

[jmauro]

Who knows whether the plane was shot down or just plane crashed. Any one who claims something either way is probably a fool.

Somalia was the result of Bush I sending troops in there and expanding the mission. The bad stuff just seemed to happen after Bush left. And who says invading Iraq during the Clinton administration would of done any good. Bush I even decieded against it when they were pummling them the first time. Bosnia was more the result of the European Union not reacting than the US. They weren't even handling it all that well until the US forced NATO to step in. There hasn't been much trouble since then. And when the hell did we ever send troops into Rwanda? Overall Clinton did OK, but worse than the left and better than the right give him credit for. He'll probably be remembered for being impeached and the continually expanding economy during his years. Probably more than some other presidents would be remembered for. Everything can be seen with a tint of bias. Remember that even Rush Limbaugh was happy to see Bill Clinton elected since he knew it would mean 8 years of steady employment.

Re:fear mongering

[mesocyclone]

What a load of .... ahistorical disinformation!

It was not clear what was happening at first. There were no fighters that could intercept in time - some were launched but didn't get there fast eough.

The fact that Washington might come under attack was not immediately obvious. In fact, nobody knew it was terrorism until the SECOND plane hit the WTC. By that time, the third plane was getting close to hitting (it was also flying low, with the transponder turned off, and was very hard to track on civilian radar). And most people don't realize that the US normally had ZERO armed fighters aloft, and only a few on standby alert for the entire east coast.

As far as the flight over PA... the crash was witnessed. It was not a military attack. The debris was not scattered over a wide area, but rather confined to the small area typical of high speed flight into the ground at a high angle.

The president wanted to return to DC. His advisors wisely suggested he do otherwise until the magnitude of the threat could be determined. It was some time before it was determined that there were no more rogue aircraft up there.

If Clinton had been president, he would have sent a few more cruise missiles up the rear of a few more camels, and then gone crying to the United Nations. Oh, and he would have blown up a pharmaceutical factory somewhere. It was Clinton who failed to take Al Queda seriously in the first place - missing opportunities to capture Bin Laden. Furthermore, Clinton's "impeachment war" was widely recognized throughout the world as a phony war meant to distract from political embarassment. As such, it further inflamed the Arab world when they saw a US President willing to kill Arabs for his own personal gain!

Oh, btw... the order WAS given to shoot down the PA flight if it came into striking range of a major target.

Re:fear mongering

[Archfeld]

Standard tactic, I've yet to see anywhere where the FCC or the FAA could point to any credible, repeatable case of interference, but heck, the terrorism effect seems to work every where else why not here as well, can't blame them for trying.

Re:fear mongering

[stinky wizzleteats]

first, he is reluctant to take military action against US civilians -- if you listen to the rhetoric coming from washington at the moment (take out saddam) you will note little indication that the loss of civilian lives weighs heavy on the minds of military planners (considering large civilian losses are expected if an invasion is to actually take out saddam).

The contrast you are attempting to make is poorly supported by the practices and doctrine of the US military, which takes incredible measures to protect the lives of enemy civilians, and by the fact that the only people being shot at in Iraq right now are U.S. pilots. I therefore find your suggestion as to the state of mind of military planners with regard to said civilians to be extremely suspect.

it's a situation that we havn't encountered but we should be flexible enough to handle these situations. a lame analogy to my line of work would be having a production server crashing while i'm eating lunch and lesurely enjoying my lunch instead of fixing the problem. the point is that people (i won't point fingers) didn't do their job.

Your lunch analogy has a very big problem in being applied to the 9/11 crisis. In your example, you have complete awareness of the problem, its scope, and the solution that is required. You do not depend on thousands of people in various organizations that lie between the president and a radar operator for the FAA to impart the knowledge that radar operator has that Something Is Wrong.

Can you identify for me a point of view, be it Air Force One, the cockpit of an F-16 searching the skies for the missing plane, a fire truck parked in front of the twin towers, or anywhere else in the country from which a clarity of vision sufficient to kill hundreds of airline passengers could have been obtained? Given the pain and tragedy of that morning, I would consider such conceit not only hopelessly divorced from reality, but also viciously unfair to those who struggled to find the right thing to do that day, many at the expense of their lives.

I spend a great deal of time studying history, particularly moments of crisis such as Pearl Harbor. I find that we are instinctively driven to find a meaning in disaster, so that we can try to create a construct of belief that we can avoid it in the future. It is therefore much easier to find blame in the actions of those in crisis than to admit that given the millions of life's uncertainties, combined with our own imperfections, nothing could have been done. I admit that it is a painful, powerless confession to make, but I simply believe that the honor of those who died that day demands it. Somehow, I think that our ability to truly learn from those events depends upon it.

Re:fear mongering

[ThrasherTT]

Yeah, I think is was the 14th St. Bridge. I remember that day pretty well even now... my father drove that bridge often, and my mother thought she saw the twisted wreckage of his truck in the mess. She called the office and was told that my father was near/on the bridge at approximately that time (he was on his way home, had just left a job site near there and was expected to cross the Potomac on that bridge). The next several hours were hellish as we sat glued to the TV waiting to get some information, while my mother went from weeping softly to sobbing hysterically and back all day.

Luckily, as we found out later, my father was driving with his boss and a co-worker, and his boss decided to go to another job site before they went home. They got lost, and he eventually called to let us know he'd be late.

Re:fear mongering

[Catbeller]

A lot of Bushies amongst the moderators this week.

Re:fear mongering

[Catbeller]

Oh, and BTW, my posting is factually correct. Bush did have sole authority to order the military to fire on an airliner. He did nothing, on tape, for most of a half hour he could have used to order the shootdown. He did flee to a safe location while Cheney remained at the White House. The "White House was under threat" story was later dismissed by the White House. And if Clinton had done what Bush had done, he would have been impeached. Especially since Bush and Rice, et al, canned the anti-Bin Laden program upon reaching office. When Clinton fired at Laden, it was "wag the dog" for months... when Bush called off the dogs, bin Laden fired and killed thousands. But Bush is a hero, Clinton despised. There is madness here.

Re:fear mongering

[ninewands]

I don't know ... I can only see the end result of all the moderations at the moment I downloaded the page with your post on it ...

I know that I, personally, M2 like the hammer of God himself, because I have seen the mod points abused to eliminate "unpopular" statements from visibility, but I RARELY metamod "Unfair".

Ok Ok - This is obvious ....

[bizitch]

This means WAR!! (driving)

Concerns

[coreman]

Well, they'd better tighten up the radars to deal with it else they've just given an off the shelf solution to interfering with these radars, and told interested parties about it.

Consider the impact of a Beowulf cluster of these!

Re:Concerns

[GMFTatsujin]

Just set all the towers to conform to the HDTV standard by 2006!

Um...

Oh, wait.
GMFTatsujin

Re:Concerns

[Daniel Dvorkin]

Yeah, no shit. Something is seriously wrong with our military radar technology if it's that easy to interfere with. I have visions of al-Qaeda stockpiling 802.11 equipment in a cave for their Next Big Event ...

Why not just use cell towers for radar?

[guacamolefoo]

Recently in the ex-Yugoslav mess, I believe that there were reports of the use of cell towers to track the "stealth" bomber, so who needs radar? Besides, is the DOD planning on bombing Starbucks? One can only hope!

GF

Re:Why not just use cell towers for radar?

[aengblom]

From my understanding, folks would simply watch the Stealth figher's come in and call in reports of the planes. Highly low tech, but moderatley effective.

Re:Why not just use cell towers for radar?

[_ph1ux_]

That and there were the people who were modifying Microwaves (the cooking kind) into radar jammers. (which would be used to lure the bombs to those locations)

I can see the military's point

[MetricT]

802.11 is only used by terrorists and degrades our ability to conduct military strikes against Starbucks...

Interference?

[wiredog]

Don't wifi/802.whatever/etc have power outputs in the milliwatts? Military radars work with hundreds of watts.

And if these technologies do jam radars, is there an application in the field of speeding ticket avoidance?

Re:Interference?

[voodoopriestess]

Most modern radars have attenuation and can handle a wide range of RF frequencies. This can be from 0.5 GHz to 40 GHz. Mobile phones and current WIFI inhabit the 2.5 GHz range (commonly refered to as CD band) and is dealt with seperately to the rest of the microwave bands (E-J and K). A WIFI adapter will NOT jam a military radar but rather show up as an unknown emitter which in a time of war will generally cause the ship/plane/helicopter to go "defensive" and defend against the potential threat!

Re:Interference?

[Detritus]

A radar may have a very high ERP (effective radiated power), but the signal returned from an illuminated target is small. You have the path loss to and from the target. That is what makes it possible to jam a radar with a modest transmitter.

Re:Interference?

[archeopterix]

Don't wifi/802.whatever/etc have power outputs in the milliwatts? Military radars work with hundreds of watts.

The generated signal may be hundreds of watts, but the received echo is far below miliwatts. Radar designers have to use really smart tricks to avoid jamming themselves.

And if these technologies do jam radars, is there an application in the field of speeding ticket avoidance?

The radars used by cops operate somewhere near the visible wavelengths (hundreds of nanometers). That is much shorter than military radars (centimeters, as far as I remember). I don't think wifi interferes with that.

Re:Interference?

[Dark Lord Seth]

A WIFI adapter will NOT jam a military radar but rather show up as an unknown emitter which in a time of war will generally cause the ship/plane/helicopter to go "defensive" and defend against the potential threat!

... meaning that you'd better have a fast vehicle if you go wardriving near any military installation because you might just end up with a HARM missile chasing your SUV down the interstate. Although if you're in a suicidal mood, you could ping something from your car and mock the HARM missile as it locks onto the emitter, which shut down after sending the echo-request packet, causing the missile to loose lock, after a bit your wifi card sends out another icmp-request packet, causing the HARM missile to momentarily re-aquire a lock onto you again, etcetera.

Can you imagine some poor pilot having to report to his CO why his HARM missile is continously losing lock in the middle of NYC?

Re:Interference?

[arkanes]

End result: you're still dead.

Not if you're moving, though :P

FCC should take care of this

[spacecomputer]

Last I checked it was the FCC that was responsible for the allocation of spectrum in the United States and territories. They are the arbitrator of interference issues. In short: I use WiFi, if there is a problem then the FCC, not me, is to blame.

Re:FCC should take care of this

[Albinoman]

I was going to reply to this in your way. This is absolutely right. Isnt the FCC supposed to check what frequencies are being used by what and allocate wavelengths accordingly? Why hasnt the NTSC complained (different frequecy radars I might guess), they are the one who actually need radar over our soil. What the heck are the military tracking other than training flights?

Re:FCC should take care of this

[Qzukk]

What is the military complaining about, doesn't their equipment have the FCC stamp on it?

The military version of the FCC stamp reads "This device must accept all interference, and is permitted to fire missiles back."

EMI? No problem.

[Detritus]

The solution.

Take time to be sure

[seosamh]

The article says that DOD only wants a delay in the consideration, blah, blah...

"The Pentagon wants regulators to delay consideration of opening an additional swath of radio frequencies..."

It seems prudent to at least explore the possibility that wireless could degrade the use of radar (for military and civilian purposes) before jumping on this issue. The key to being responsible about it is to move quickly on the necessary research.

Priorities

[Genuine669]

Maybe I'm wrong, but being an up and coming naval officer myself, I don't think there is much of an argument. Radar or wireless internet...radar or wireless internet... or maybe they could combine both..you know, ping someone, find their lag....and their distance =)

Re:Priorities

[jhealy]

Good to know our up and coming naval officers have a good grasp on the concepts of contemporary technology.

Re:Priorities

[m0rph3us0]

... because when our planes start bombing our cities in the hunt for the terrorists I'd really hate to interfere with their bombing abilities ny the use of my WLAN.

Just wait till the gov't finds out that the microwaves in our house transmit at similar frequencies to those that my WiFi card emits, except they do it at 700W.

Maybe we shouldn't build our radar systems in the public spectrum.

1. Buy microwave
2. Remove shielding
3. Sell "radar jammer"
4 ?? Proft.

Typical Military BS

[Boulder Geek]

Choice quotes: "might cause interence", "not right now, but maybe in the future"... This is the Pentagon spreading FUD, and knowing the predilictions of the current administration, it all bodes very ill for wireless in general and WiFi in particular. In my quick scan of the article I didn't see any mention of 5Ghz or 802.11a, so it rationalizations that the Pentagon is looking at the UII band are misplaced.

Consider yourselves warned.

Re:Typical Military BS

[shylock0]

Yeah, but I think the broader point is that it "might" cause interference; nobody knows, and the military just wants to put things on hold to test things out. Note that they talked not just about tracking systems, but also about possible interference with missile guidance. The people over at the DOD who work on these things all have PhDs in physics, so I'm assuming this isn't all BS.

It would be a real, real shame if wireless tech interfered with long-range weapons systems so that, say, wireless tech in Israel caused enough interference for smart bombs in Iraq to hit a hospital instead of a weapons depot... I'm not saying its possible, I'm just saying that the possibility needs to be investigated, so that the military can redesign their systems to fix the problem.

Re:Typical Military BS

[GMontag]

The "BS" factor may well be within the writing of the article. The feds have plenty of PhDs working on this, but what of the somewhat anti-military New York Times?

Re:Typical Military BS

[ryanvm]

Choice quotes: "might cause interence", "not right now, but maybe in the future"... This is the Pentagon spreading FUD

You're right - because we all know that heading off problems before they happen is a bad idea. Exactly what is wrong with a state agency issuing a statement that there is the potential for interference and that further investigation is warranted?

and knowing the predilictions of the current administration, it all bodes very ill for wireless in general and WiFi in particular

Huh? George Bush hates WiFi? WTF are you talking about? Lemme guess - you're referencing this article. In case you didn't read it, it basically says (according to Wired no less) that the Department of Defense thinks that open wireless networks have the potential to be dangerous. Guess what, they're right. Do you know how much damage even the lamest script kiddie can do from an open WiFi network? The danger comes from the fact that they're utterly anonymous. If he gets caught fucking up someone's network all he has to do is start his car and *poof* he's untraceable. That's pretty dangerous.

Re:Typical Military BS

[Catbeller]

You're right - because we all know that heading off problems before they happen is a bad idea. Exactly what is wrong with a state agency issuing a statement that there is the potential for interference and that further investigation is warranted?

Because they have no evidence of any such interference, or theoretical possiblity of such, and there are political and commercial objectives in suppressing WiFi, what they are doing is FUD -- intentional spreading of misinformation and leading questions to an advantageous end -- for them.

As for the kiddies -- here's the thing. If the military and commercial forces keep their hands off of consumer-grade self-built 802.11x networks, the only people using it will be civilian enthusiasts. If a script kiddy brings down a segment, no big woof. Why should this be a government matter? Other than the fact that some in the big guv, and in corporations (same thing, really)want control of theses networks handed over to them, right now.

It is FUD, as a means to an end: control.

Re:Typical Military BS

[krlynch]

Because they have no evidence of any such interference, or theoretical possiblity of such,

Just because the NYT doesn't go into a detailed description of the problem, supported mathematically with physically rigorous arguments does not mean that the DOD guys have no evidence of a problem or theoretical reason to be concerned. That is, absence of evidence about this potential problem in the article is not evidence that there is no potential problem in the field. Reallocation of spectrum, or sharing of spectrum between new devces and old devices that were not designed with the new uses in mind always has the potential to lead to unacceptable interference.

The concern is about new hardware that does not yet exist and is targetted for spectrum that has not been allocated for its use. The burden to prove that there will not be backwards compatibility issues in opening the spectrum to new use in on those wanting the access (the WiFi industry), not on those that already have access (ATC, weather radar, etc.) The argument in favor of opening the spectrum given in the article is a variation of "Trust us, it won't happen." Which may or may not be a faithful representation of the industry argument.

Because of the circumstances, the theoretical arguments you claim don't exist actually do exist, and rather clearly come down on the side of the DOD in this case: it is a trivial matter of freshman physics to show that ANY multiple uses in a restricted geographic area of the same chunk of frequency can lead to interference. Which does not mean that in practice there will be issues with WiFi; the industry arguments may be correct, and interference may be a non-issue. THAT appears to be the DOD's main concern: what will happen in practice. So the question that DOD thinks should be answered before the spectrum reallocation occurs is: Are the guarantees given by the manufacturers about their anti-interference measures strong enough? I for one would prefer to find out the answer before planes fall out of the sky.

Re:Typical Military BS

[ryanvm]

Because they have no evidence of any such interference, or theoretical possiblity of such

They're not concerned about 802.11b, that operates in the 2.4 Ghz band. They're talking about 802.11a and any other WiFi technologies that use 5 Ghz. Anytime two techs use the same frequency in the same area you are obviously going to have a potential for interference. No doubt about it.

there are political and commercial objectives in suppressing WiFi, what they are doing is FUD -- intentional spreading of misinformation and leading questions to an advantageous end -- for them.

Get serious. Nobody in Washington could give two shits about WiFi, and for good reason - WiFi isn't threatening anybody's business model. Name one 802.11b based ISP that is actually pulling in a profit.

In its current form (802.11b/a) WiFi just doesn't work well in a widescale (citywide) deployment. It's too damn sloppy and prone to interference. Any WiFi tech that uses an unlicensed part of the spectrum is going to suffer from the same affliction. You can't base a business on selling what is essentially public property.

There is a reason that WiFi areas are called "hotspots" - because they're small. 802.11a/b will never be useful as a metropolitan networking medium for a large number of people.

If the military and commercial forces keep their hands off of consumer-grade self-built 802.11x networks, the only people using it will be civilian enthusiasts. If a script kiddy brings down a segment, no big woof. Why should this be a government matter?

You're missing the point. Regardless of who owns the networks, if they allow anonymous access they are a very dangerous tool. I'm not talking about the script kiddie bringing down the wireless network, I'm talking about them launching attacks across the Internet from an untraceable IP address.

What is to prevent me from downloading every script out there to my laptop and then driving to the nearest public access point and attacking every web site on the Internet? I could be as sloppy as I want and nobody will be able to track me down. Right now, if I launched that kind of attack from my cable modem I'd have the feds knocking on my door in 24 hours. That's why the DoD cares.

Suggestion for Saddam

[nomadicGeek]

Get on Amazon and order a whole mess of Linksys WAP 11's. Then get a hand on as many Pringles cans as possible (Pringle can antenna article) . This is the cheapest missile defense system you can build.

Re:Suggestion for Saddam

[nomadicGeek]

In related stories....

The Bush administration introduced a resolution to the UN Security Council to limit access to Pringles cans and other dual-use technologies.

John Poindexter demonstrated the usefulness of his new All Watchful Eye database. By querying the database, he was able to instantly produce a list of all Iraqi's who have purchased Pringles in the last year:

"SELECT LASTNAME, FIRSTNAME FROM LISTOFEVERYONEANDEVERYTHING WHERE NATIONALITY = 'IRAQI' AND PURCHASE LIKE 'PRINLGLE'"

Tariq Aziz refuted claims that the evil Iraqi dictator starved his people to funnel money made from UN sanctioned oil sales to his weapons development by producing pictures of well fed Iraqi children being forced to eat Pringles.

Sean Penn who was previously reported to be in Iraq to protest war was actually found to be drawn to the country by a powerful case of the munchies. When confronted with this allegation, Penn responded that it was "totally bogus" and told the reporter to "stop being such a dick, dude". He then offered to help an Iraqi technician with his Pringle can claiming that his dad was a TV repairman and had an "awesome set of tools".

I can hear it now...

[trix_e]

Mr. President, about, uh, 35 minutes ago, General Jack Ripper, the commanding general of, uh, Burpelson Air Force Base, issued an order to the 34 B-52's of his Wing, which were airborne at the time as part of a special exercise we were holding called Operation War Driver. Now, it appears that the order called for the planes to, uh, attack their targets inside Russia. The, uh, planes are fully armed with nuclear weapons with an average load of, um, 40 megatons each. Now, the central display of Russia will indicate the position of the planes. The triangles are their primary targets; the squares are their secondary targets. The aircraft will begin penetrating Russian radar cover within, uh, 25 minutes.

It, uh, appears that the whole misunderstanding was caused by a Wi-Fi access point in a Starbucks in Schenectady sir that confused General Ripper's signal corps.

Re:I can hear it now...

[yack0]

Mr McKittrick, after very careful consideration, Sir, I've come to the conclusion that your new Wifi network sucks.

Re:I can hear it now...

[volsung]

I'd piss on a sparkplug if I thought it would help me check my email!

Could or Might interfere?

[Blindman]

Basically, the article says that WiFi might interfere with Radar. I don't think anybody wants that, so rather than just scare everybody, they should do some studies and find out. If it does, they will most likely restrict the locations that it is available, and if it doesn't then we should move on to more interesting problems.

What goes around comes around...

[skaffen42]

So they complain when something might interfere with their navigation, but not when they interfere with the navigation of whales?

Dual standards as usual...

In a war room near you...

[Kredal]

"Sir, there's a wireless access point at 30,000 feet, coming straight for us! The good news is, we can anonymously surf pr0n for the next 15 minutes... the bad news is that the access point is loaded with 50 megatons worth of bombs!"

In Soviet Russia,

[adb]

you screw nyt.com.

Huh?

[Fnkmaster]

Didn't it occur to them to talk to the FCC about this, and the standards bodies that set up the 802.11a standard BEFORE products were out there on the market? If they missed the boat with this, then somebody's fucking head should roll. What a bunch of idiots. Fire whoever is responsible for failing to bring this up in the first place and make them personally liable for business losses to companies if they have to pull products off the market. That'll teach em.

Re:Huh?

[Fnkmaster]

I did read the article, you troll. The DoD is whining about "possible effects" of WiFi, though no such effects have been observed, and bitching about opening up the 5Ghz spectrum for further usage. But the cat's out of the bad already - 5Ghz is already being used by 802.11a, thus my point that they missed the boat and should have brought this up when 802.11a was in the standards process if they think it's a possible problem.

Nope.

[glrotate]

According to this article it was a modification of existing radar.

Some aviation experts suspect the Serbs used a crude version of passive radar -- plugging computers into their existing air defense system -- to locate an F-117A Nighthawk stealth bomber, shot down in 1999.

Also from the article:

John Hansman, professor of aeronautics and astronautics at the Massachusetts Institute of Technology, said passive radar is still in its "infancy, but is something that will lead to new stealth research."

"This is another trick that will force stealth researchers to push forward," Hansman said.

All in all just another iteration in spy v spy.

Re:Nope.

[guacamolefoo]

According to this article it was a modification of existing radar.

According to the same article, it was also radar based on interpreting cel tower signals:

"WASHINGTON (AP) -- America's stealth bombers may be in danger of having their cover blown by a new type of radar that uses cell phone technology, researchers say.

The Air Force says the problem is limited and America's stealth fleet is in no danger. Yet U.S. intelligence reports label the radar a serious threat, and several scientists say they agree.

"We're talking about radar technology that can pinpoint almost any disturbance in the atmosphere," said Hugh Brownstone, a physicist at the Intergon Research Center in New York who has worked for the cell phone giant Nokia.

"You might not be able to distinguish between a stealth plane and a normal one, but you might not need to," he said. "The point is, you can see the stealth plane as a blip."

The potential risk comes from radar towers used by cell phone companies to draw in signal patterns. The new technology, called passive radar, watches signals from common cell phone transmissions. When a plane passes through, it leaves a hole in the pattern, giving away its location.

Traditional radar -- the kind stealthy B-2 and F-117A bombers can fool with their angles and radar-absorbing paint -- sends out signals and waits for them to bounce off large objects in the sky and return."

GF.

Re:802.11 and police radar

[greechneb]

It is probably if that was done, and proven intentional, you'd end up getting screwed.

Most states outlaw radar jammers anymore I believe.

SETI Concerns?

[dagg]

If the military is indeed concerned about the expansion of WIFI systems, I wonder what the SETI project thinks? Does anyone know if it makes any difference to them?

Re:SETI Concerns?

[1fitz2many]

I think all astronomers, not just SETI folk, are concerned about interference. Remember, these signals may not look like random noise.

Radio interference is a problem in astronomy that continues to grow. Astronomers consider the amount of interference as an important factor when choosing sites for new arrays, sometimes situating them in valleys to help mitigate these effects. Indeed, there are radio-quiet zones around major facilities, where (e.g.) cell-phone use is prohibited.

I'm sure some astronomers would be smirking at the military now getting concerned about interference problems (when the military generally didn't care about their systems interfering with astronomy), if it were not for the fact that these problems affect us all.

Baloney!

[cosmosis]

Dbrower - you are absolutely rigght. All of this stuff about interference is pure BS. Software Defined Radio combined with Open Spectrum renders interference problems obsolete. Ironically, it was the military who invented software defined radio in the first place!

I would say this has more to do with either pure ignorance on the part of the DOD, or an excuse to squash this liberating technology.

Planet P Weblog - Personal Liberty with Technology.

Re:Baloney!

[krlynch]

More likely than ignorance, they (DOD scientists and engineers) are probably concerned that this new use of spectrum previously allocated for air traffic control, weather data collection, and defense purposes will cause problems for OLD radar equipment that IS NOT capable of changing frequencies. You know, the backwards compatibility problem. There are billions and billions of dollars worth of government (military and civilian) radar systems that could be affected, and no one is talking about paying to replace or upgrade those systems to eliminate the potential for interference.

Reading (somewhat between the lines of) the article, I find explicitly or implicitly the following points:

• There exist critical radar systems for civilian and military air traffic control, as well as weather radar that CAN'T change the frequencies they are operating on.
  
• The spectrum they have been allocated and are currently using is a logical location to put new WiFi capabilities, in geographic areas where they won't cause radar interference.
  
• In areas where there is potential for interference, the manufacturers of new WiFi gear have designed their new systems to choose spectrum such that they don't interfere with those radars, in anticipation of those spectrum bands becoming available for such use.
  
• The DOD is concerned that these designs do not provide sufficient guarantees that they won't cause the interference DOD is concerned about
  
• The industry is unwilling (either because they don't think it is necessary, or they don't want to spend the money ... take your pick) to go back to the drawing board and make stronger signal isolation guarantees.
  
• The two sides are lobbying the FCC to see the truth of their beliefs.
  

I don't see a big conspiracy here ... just two groups of people that don't quite agree with the technical points raised by the other side, and a number of issues that need more study before everyone will be happy.

While I wouldn't mind faster and more capable WiFi, I'd much rather that the tech industry be forced to make changes to ensure that interference won't be a problem NOW than having to do so AFTER someone's web surfing causes a plane to disappear from air traffic control screens ....

Re:Baloney!

[mesocyclone]

Baloney yourself!

Neither software defined radio nor the Open Spectrum initiative renders interference problems obsolete. Saying otherwise is about as meaningful as saying that modern computing repeals the 2nd Law of Thermodynamics!

Radios of any sort increase the energy in the bandwidth that they use. This is true whether they are narrowband traditional radios or ultramodern, cellularized, spread spectrum or ultra-wideband radios of the future.

Any radio receiver has to pull its desired signal out of the ambient noise. That noise consists of natural noise (thermal noise, spherics, astronomical sources, etc) and man-made noise (either noise-like signals or coherent signals). Many radio systems must operate close to the theoretical edge of practicality. The military and reconnaisance organizations especially need to operate with very small noise margins - their ability to do so is one of their advantages.

Increasing the ambient signal levels do degrate the capabilities of these systems. That is trivially proven.

Open Spectrum is an approach to improve bandwidth sharing. That is all it is - it is not a magic panacea that somehow makes interference vanish. Software Defined Radio is simply processing radio signals in software. It also doesn't change the underlying physics.

Consider the issue of radar... radar operates with an inverse-fourth law (the radar equation). The return signal is inversely proportional to the fourth power of the range. Normal radio operates by an inverse square law. Thus radar is especially vulnerable to interference.

To put a little numeracy in here... let's look at a 5GHz space based radar. Assume it outputs 1000 watts peak power (power is very expensive in orbit, you know) from an altitude of 150 miles. Assume the antenna shapes this to 100,000 watts effective radiated power (ERP).

By the time this reaches the earth, it is about 1E-7 watts per square meter. Assume the radar wants to image an area of 100 meters. This is 1E-3 watts or 1 milliwatt. A *single* WiFi stations puts out 10s of milliwatts. Thus if you have one WiFi per 100 square meters, you will have ambient "noise" of 20-30 decibells above the radar signal.

So, this is not a trivial issue. Of course, coherent integration can overcome much higher SNR's, but only at a cost (it requires much more time per resolution area, reducing the overall capability of the system).

In other words, there ain't no free lunch.

The Pentagon has the services of the best experts around to advise it on issues like this. Discounting their objections out of hand is arguing from either ignorance or opinion, not science or engineering. Determining whether their objections are appropriate in this case is a matter for analyses far more complex than will appear on slashdot, and in some cases, probably will require access to very sensitive classified information.

Re:Baloney!

[rnturn]

I can just imagine what the meetings with the Wireless, DoD, and FCC people are like. Some years ago, I was involved in developing a PC software package that was being used by the FAA to determine whether proposed FM transmitters were going to adversely affect ILS approaches. (And before anyone chimes in with some comment about FM not being in the ILS band, consider IM harmonics.) While I never got to attend any of the meetings with the broadcasters (or the wannabees), the FCC, and the FAA, I was told that the discussions were quite heated and that our software was under attack by the broadcasters at every step of the way despite it's abililty to predict interference quite nicely and verified by flight test measurements numerous times. (One of the more interesting results was an audio recording of a ball game recorded from the front end of an ILS receiver). And like krlynch's comment on old radar equipment, it would have been unacceptable to allow a new transmitter that would force existing GA aircraft to undergo expensive avionics upgrades merely because someone decided that a new easy listening FM station was `needed'.

Based on that experience, my guess is that the moneyed Wireless interests will be fighting this battle from an economic point of view and not from a technical one. (Unless they want to make the ridiculous argument that all of the existing equipment that they're interfering with should be replaced.) What'll be interesting is the stand that the FCC takes as (at least), traditionally, the party that interferes with an existing spectrum's use is the party that has to make a change. With the Powell FCC seemingly happy to cowtow to whatever economic argument they are presented with, it makes you wonder whether the traditional policy will continue to hold sway. Or will an airliner collision or two be needed before the use of the spectrum for radar is protected?

``The two sides are lobbying the FCC to see the truth of their beliefs.'' (emph. mine)

Good grief I surely hope that's not what's happening. Whatever happened to presenting data that demonstrates that the interference whether exists or does not? The FCC should not be listening to anyone's ``beliefs''.

Re:Baloney!

[GooberToo]

I would say this has more to do with either pure ignorance on the part of the DOD, or an excuse to squash this liberating technology.

Certainly sounds reasonable considering a large enough network built using wireless could effectively prevent a large segment of traffic from ever going across major backbones. That means in some instances, the DoD's net and ISP sniffing technologies will be greatly snubbed.

Re:Baloney!

[SN74S181]

Oh yeah.

It's The Man keepin' us down some more.

Write it up for your leaflet.

Re:Baloney!

[mesocyclone]

Well... actually I was considering synthetic aperture radar, which reduces the physical antenna size requirements (to zero in the case of scatterometry).

Re:Baloney!

[cosmosis]

Well, this is all impecable physics I must say. As a physicist myself I am impressed with your working knowledge of electromagnetics. But you are still missing one very important part of the equation - computation. With sufficient speedy processors, all of this so-called interference gets process from very low signal/noise ratio to very high signal/noise ratio. With sufficiently advanced speed and algrothimic elegance, the sky IS the limit to the number of channels that can exist on any single frequency.

Planet P Blog - Personal Liberty with Technology.

Re:Baloney!

[stu72]

I don't see a big conspiracy here ... just two groups of people that don't quite agree with the technical points raised by the other side, and a number of issues that need more study before everyone will be happy.

omg - someone pinch me - I think I just encountered rational thought. Is that allowed on /.? Or anywhere? Am I the only one who feels overwhelmed by "everything is a conspiracy" propaganda spouted by would-be social and political commentators at every water cooler?

Keep this up and next you'll be telling us that you don't think the US is the root cause of all evil in the world, past, present and future. Seriously, I am waiting for the day when I will hear, "I just stubbed by big toe on my table and wouldn't you know it - the table was made in the USA - those damn americans - I knew they were out to get me!"

Re:Baloney!

[mesocyclone]

Would that this be true! But it is not. Check out Shannon's laws.

The way you separate signals from noise is ultimately by integration. The longer you integrate, the lower the signal to noise ratio you can tolerate. BUT... that limits the information rate - I can pull one bit per second out of pretty deep noise - either by coherently integrating for a while, or by sending it in a very narrow band way and using very narrow filters (which equates to long integration - there ain't no free lunch).

Any modulation scheme and data recovery scheme you come up with boils down to this same limit. This even applies to ultra-wideband technology, which is, at low signal levels, no different than spread spectrum.

All that speedy processors ultimately do is perform the same functions that analog systems can do now. They just do it vastly less expensively (for certain algorithms - say phase linear sharp filters) and with more precision (in almost all cases). But even the act of converting into the digital domain reduces the signal to noise ratio through quantization noise.

If you don't believe that there is a fundamental limit, I suggest you propose an algorithm for extracting the information. Let's use a simple modulation scheme and here we go:

The signal at the receiver is at a level of -174dBm (decibels referenced to 1 milliwatt).

The receiver is operating at 273 degrees Kelvin
with the standard input impedance of 50 ohms resistive.

The modulation scheme is simple phase shift keying (a 1 = phase 0, 0 = phase 180).

The modulation rate is 100kbps.

Go for it!

Re:Baloney!

[cosmosis]

I suggest all of you read this before continuing with your traditional physics based explanation. This article is by David P. Reed, famous for Reeds Law. More importantly this paper was presented to the FCC.

Re:Baloney!

[mesocyclone]

I read that paper some time ago. I just read it again. It contradicts *nothing* that I have said.

If you believe otherwise, I would suggest you extract the specific assertion and make it here.

The paper is about how smart networks can increase the bit rate per area per megaherz. This is not exactly black magic. Cell technology is a primitive (and in some cases, not so primitive) example of the principle.

As I said before, "open spectrum" and "software defined radios" (or more apropos to that paper, smart radios) do not remove the issues of interference.

They are simply clever ways of dealing with the issue that *improve* spectrum usage. They do it through a number of techniques - but ultimately there are three principles:

1) Time/Frequency multiplexing - using intelligence to make it more effective than past systems. This includes spread spectrum (already used in cellular), ultra-wideband techniques (a special form of spread spectrum), collision avoidance (chosing a temporarily available frequency), and various levels of local cooperation.

2) Area multiplexing - the cellular principle, but with more flexibility and intelligence. Basically one reduces the power of the radio because one is talking to a more local resource.

3) Relaying through the network to avoid long haul transmissions - something amateur radio packet networks have been doing for decades.

NONE of these techniques eliminates the problem of interference. NONE of these techniques relies on any new physical or computational principle which magically makes the problem go away.

ALL of these techniques are already in use at one level or another, and all still boil down to the same fundamental issues: signal-to-noise ratio limits the channel carrying capacity (as is pointed out in the paper that *you* referenced). These techniques simply provide for the re-use of channels in space and time - and nothing more.

Put another way... old fashioned spectral regulation uses fixed frequencies with guard bands and power limits (and other limitations more technical) to avoid interference. Open Spectrum (a movement of which that paper is a part) uses smart radios to achieve the same effect, resulting in a significant increase in spectral efficiency (in fact, potentially a vast increase). Those techniques may actually *increase* the total amount of man-made radio noise, as seen from a distance (say - a space based military radar or a radio telescope).

Finally, it is important to recognize that Open Spectrum has several dimensions: technical, political and economic. Many of the proponents of open spectrum are more informed on the latter two issues than the former.

Open spectrum does *not* reduce, for example, government regulation. What it does is use highly detailed and technical regulation in a general fashion to produce a spectral space where individual regulation (station licensing) is not required. THAT is a significant improvement economically and politically. In other words, it regulates the characteristics of radios, rather than the users of those radios. This exists today in some areas - for example your don't need a license to use a cell phone, but the cell phone *does* need an FCC approval (on very detailed technical grounds) before it can be legally sold or used.

In the technical area, Open Spectrum (in many variants) replaces one set of problems with another, and hopefully in the process produces more value to spectrum users. The problems it removes are guard bands and individual stations licensing.

The problems it adds include increased radio complexity; more difficult testibility; more system robustness at the cost of typically less predictable for a single station; hidden station issues; tolerance of defective radios (which may violate the protocols); tolerance of intentional "commons" hogs (see citizen band radio for an example) ; difficulty in interference prediction ; individual system failure if stations *happen* to get too close together.

All of these can be dealt with, and will be.

Just don't tell me that the radio interference has magically vanished because of this stuff. It hasn't, and it won't.

Re:Baloney!

[cameldrv]

You use SAR, and the best guess of the civillian world is that the current satellites get 1m SAR resolution.

Won't someone think about the Whales?

[Flamesplash]

Apparantly this only works one way. There have been a lot of articles out lately about Navy sonar and other artificially generated waves interfering with Whale communications.

I wonder what they would do if the Whales went and destroyed facilities developing the devices that mess with them. Now if only they could get them to do the main development on ships, then the time of the Whale will come upon us. MWUAHAHAHAHA

This is about 5Ghz technology

[goombah99]

Despite the misleading headline inserted by slashdot editors, the article refers to an"increasingly popular" wireless technology in the 5Ghz band.

The pentagon is not trying to poop on the wifi party. And they are not out to supress info transfers. They just want to make sure that a stupid irrversible giveaway of the wrong band does not take place. Apparently a lot of next generation radars need this band and depend upon a noise free environement. for example the article notes weather radar. Believe me getting a radar return of gas is very very difficult. Even high power radars are not the whole answer--the return signals are weak and fall off 1/r^2 limiting the range.

My fear is that the bush admin will give way to the coroprate interests. Microsoft is one of them mentioned in the article. these companies have dumped tons of money into campaign contributions. And the easy thing for the bush admin to do is to do nothing at all.

regardless of your misgivings about the department of defenses other activities, having good radar is a swell idea that we all can benenefit from.

presumably there might be some techno fix that could make all happy. But remember these radar systems take years to design. Its not just about making the latest up-to-date technology but also about quality assurance, standards and interoperability. So just saying they could be redesigned is not a valid response. You dont retrofit safety systems on a whim because some thinks they can make it better. Murphy's law will get you. And its often better to have standardized less than state of the art systems people know the limitiations of than a myriad of superior technologies they dont know the relaibaility of.

Re:This is about 5Ghz technology

[archeopterix]

Shouldn't it show the DoD that they should start work, today, on the next-next generation of radar, which won't be able to be foiled by a bunch of high-power 5 ghz transmission devices, the basic parts for which might soon become available from civilian outlets over the Internet.

It's not that easy to jam a radar. Bats are a living proof of this. Thousands of them can navigate in dark caves without jamming each other. Radars are designed to avoid jamming - they use quite a wide spectrum of radio waves that changes dynamically (bats do that too, only with sound waves). Of course it is probably possible to build a jamming system, but such a system would involve many high-powered transmitters and thus would be very costly. I guess that widespread use of radar-frequency Wi-Fi would just slightly degrade military radar performance (perhaps civilian aviation radars would suffer more) and that's what the military are concerned about. I would be more concerned about a kilowatt radar signal damaging Wi-Fi equipment though.

Re:This is about 5Ghz technology

[Matt_Bennett]

the return signals are weak and fall off 1/r^2 limiting the range.

Ok, this is nitpicking, and the poster makes a strong point, but I think that there is one point that needs to be corrected, which makes the situation even worse- the transmitted signal falls off at 1/r^2, and the reflected signal falls off at 1/r^2, so the radar return actually falls off at 1/r^4!

When it comes to safety issues, the regulatory bodies are very conservative, and because of the massive amounts of infrastructure it requires, changing things will take a long, long time. There is a finite amount of useful (right now) spectrum, and we have to carefully balance convenience and consumer demand (Wi-Fi) vs. safety.

Re:This is about 5Ghz technology

[goombah99]

Mentioning that signals drop off at r^-2 actually works against you: Wifi signals, weak to start with, will decay extremely rapidly

Well actually I was wrong to say it falls off as 1/r^2 it actually falls off as 1/r^4 for the received signal. On the otherhand the wifi transmiters are interfering directly so they fall off only as 1/r^2. And actually it is worse than that. Since the wifi transmitters are distributed they sont actually fall off at all. they have a constant power density. Or if you want to say the radar is located on the perifery of a long line of wi-fi emitters then it falls offa s 1/r. in any case its a not a negligble source of noise.

Re:This is about 5Ghz technology

[cybermace5]

Ummm...wouldn't that be 1/(2r)^2? Since you're doubling the radiation path? It's not like the reflected wave is going to dissipate in five-dimensional space....

Re:This is about 5Ghz technology

[Matt_Bennett]

Nope, if it's a monostatic radar (TX and RX at the same place)- the path from the radar to target is r, so power incident upon the target is C/r^2, (C is a constant that relates to power, antenna gain, and so forth). You multiply that times the radar cross section to get the amount of power reflected and then multiply that by 1/r^2 again to get the incident power back at the radar. The power at the reciever is proportional to 1/r^4.* The r^4 term is one reason that jammers have such an advantage (their power only drops off at 1/r^2).

If you're really interested in it, check out Merril Skolnik's book, "Introduction to Radar Systems," Chapter 1 (I think) where he generates the "radar equation."

* Of course, this is all assuming that you are far enough away from the antenna to be in the far field, but if you're not, you really don't have to use a radar, you could probably hit the target with a well thrown rock.

Re:This is about 5Ghz technology

[cybermace5]

There's one thing about that I can't swallow just yet.

My reasoning is that the radar transmitter is essentially a point source, therefore the radiaton will follow the inverse-square rule. When it hits a surface, the beam has already diverged, and the rays will reflect opposite the angle of incedence. This means that the rays of the reflected radiation still follow the same path, only reflected a certain angle from the original path. This means that the rays diverge at the same angle as before, which is simply a continuance of the 1/r^2 divergence from the original point source. For the return path to tack on another 1/r^2, it's like throwing a rubber ball at a wall, and it bounces back at 45 degrees.

Of course, if radar junkies treat the object as if it absorbs the radar energy and *then* re-emits it as a point source, I can see the r^4. Does the EM wavefront actually enter the conductor and then do transmission/reflection within the metal of the object before coming back? It's been a while since electromagnetics, and we never really focused on radar (and I've been stuck doing a mechanical engineering job, but that's another story). If you can explain why the reflection object becomes another point source, I'm glad to learn all the useful facts I can (especially if they contradict my intuition).

Re:This is about 5Ghz technology

[Matt_Bennett]

Electromagnetic radiation coming from a discrete source in open space (not a wire that goes to (effective) infinity like a power line) is always proportional to 1/r^2- it may radiate more power, but that's a factor of the radar cross section- remember I said proportional? There may be a constant in front of the 1/r^2. There are other factors like antenna gain and antenna power, but those are part of the constant- Since I have Skolnik's book in front of me: Pr=(Pt*G*Ae*sigma)/((4*pi)^2)*R^4, where Pr is power at the reciever, Pt is transmitted power, G is the antenna gain, Ae is the antenna aperture size, sigma is the radar cross section, and R is the range to the target.

Flipping through the book some more, I think I've found the real source of your inability to swallow- you're thinking in terms of light- where the wavelength is incredibly small in proportion to the size of the target (called the optical reigon in radar cross section-ese). Radars typically operate in the Rayleigh region, where the radar cross section varies as wavelength^-4. In between the Rayleigh and the optical region is the Mie or resonance region- we don't want to go there- it's really hard to work there, because the RCS can vary by 400% with a small change of the target (angle to the radar, typically).

Re:This is about 5Ghz technology

[cybermace5]

I'm pretty familiar with the concept of antenna gain and the fact that we're talking about a proportion rather than exactly 1/r^2.

I grabbed my own book from a wireless communications class a while back (Wireless Communications, Principles and Practice, Theodore S. Rappaport).

It states that for large, distant objects that induce scattering, that analysis based on diffraction and physical optics can be used to find the scattered field strength. It then goes on to describe the bistatic radar equation which I believe simplifies to something like your formula:

P[R](dBm) = P[T](dBm) + G[T](dBi) + 20log(wavelength) + RCS[dB m^2] - 30log(4*Pi) - 20log(d[T]) - 20log(d[R])

Obviously T and R are for transmitter and receiver, and RCS is the radar cross section, and G is the antenna gain (and Rappaport did like those logarithms). The book says this equation describes the propagation of a wave traveling in free space which impinges on a distant scattering object, and is then reradiated in the direction of the receiver . Which means my secondary "ok, that's why" explanation is pretty close. Yeah, I was thinking in terms of the particle behavior of light, because I was tired and didn't want to visualize a giant EM wave wrapping around an airplane.... ;-)

Thanks for staying with me on this, so that I finally had to dust off my old book and lose the 6th grade physics reasoning.

When we give up WiFi

[einstein]

the terrorists have already won.

Re:Other problems as well

[aborchers]

Interference of cell phones with avionics is a red herring. The real problem with using cell phones on airplanes is that at high altitude and speed, a cell phone hops towers too frequently.

The case for avionics interference is actually quite weak, from all reports I've heard. The policy for cell use on aircraft is partly CYA, partly greed (use our in-flight phone instead) and partly a cookie to the cell industry, which cannot or does not want to deal with the hassles of supporting high-speed tower-hopping on their networks...

Ha ha! (and 1984)

[famazza]

Forget it! This will be another great technology that will no longer be avaiable in US.

But pay attention, acording to Goldenstein (984)continuous state of war serves as an excuse to cut civil rights avoiding protests!

Re:Ha ha! (and 1984)

[ctr2sprt]

4, Insightful?! How is this not just offtopic, troll-bait FUD? He makes exactly one meaningful claim and provides zero reason for believing it. His other "claim" is supported by a fictional character and is only related tangentially to the topic. (I believe the line of "reasoning" he's using here is "the DoD is talking, the DoD is in charge of wars, Bush runs the DoD, Ashcroft is a Bush employee, therefore the DoD is trying to start a war so Ashcroft can restrict our civil rights." That's about as far off-topic as you can get.)

I guess this works out to a simple "mod parent down" post. So here's something on-topic. I remember reading once an article complaining about how some medical groups are trying to stop people from drinking alcohol at all, for the usual reasons. The article was saying that, if you live your life never doing anything unhealthy, you're going to have a pretty miserable life; and that unhealthy things, in moderation, can have many positive effects (psychologically, for example). My response to that article was: "It's the job of those groups not to consider anything except our health. We, as individuals, need to make the decisions on what's more important to us, and what our definition of 'moderation' is."

My point? It's the same deal here. Of course the DoD is only going to be concerned about how a civilian technology affects military technology. It's their job. It's the job of other agencies, like the FCC and Congress, to decide whether the military's concerns outweigh those of the civilian sector. Don't read too much into this. I think it's perfectly valid that the military has a say in how something like this might work out (especially if it interferes with airport radar and such, which have critical peacetime uses). If you are very concerned as this, you should, as always, write your congresscritter (especially if he's on one of the oversight committees that deals with this sort of thing).

The wrong target?

[bald_spot]

According to This article, The most important source of interference in the band is commercial microwave ovens, of which there are over 100 million in use in the US alone.

Home radar jamming?

[OYAHHH]

I've,

Done a lot of civilian radar track data analysis and I can tell you that radar data is already littered with LOTS (and I mean LOTS) of inaccuracy.

I've seen cases where the data loss was so bad that I can hardly imagine the situation where joe-schmoe-bin-ladin with his laptop and homemade radar jamming equipment could make it any worse.

It's one of those situations where if you knew what the ingrediants were you might not want to eat it.

I certainly don't have a problem with the DOD wanting to limit radio encroachments into vital wavelengths.

But, sometimes I get the feeling that the military is crying wolf when the wolf has been there the entire time and nobody in the know is brave enough to admit it.

Re:Home radar jamming?

[pmancini]

There is a reason why they have transponders on Air Craft. It makes the aircraft stick out and above the noise. I've had a few tours of FAA ATC facilities and I got one of the last civilian tours on Sept. 8th 2001. I have seen both the old tech and the new stuff and I can say this - radar's pick up lots of stuff. Like what, you ask? Signs. Trucks on the highway. Church Steeples. Yeah, no kidding. Luckily the ATC consoles allow you to filter out most of this stuff, though some controllers keep some of it in as it provides a handy map reference... :)

I hear that the FAA is looking for anyone with knowlege of porting software from jovial to C++. Heh, now there is an esoteric job requirement!

Already wireless available in airports...

[MImeKillEr]

....these airports, to be exact.

Anyone ever hear of any planes crashing at any of these due to the 802.11 WAPs in use? No? I didn't think so.

make them stop!

[six11]

"Hello, is this the Bad Guys? This is Col. Sanders of the US Army. Listen, do you think you could tell your advancing armies to please stop jamming our systems with those pesky wireless networking signals? It's really making it difficult to prevent you from invading us. What's that you say? We should have thought of this? Well, yeah, we did, but we dealt with it by telling our citizens to knock it off. Hey, it worked for them, why should it be any different with you?"

Re:make them stop!

[SuiteSisterMary]

I wonder if HARM missles; which home in on radar sets and the like from their own emissions, would also home in on your little Linksys AP at that point...hmmmmm.

Yeah riiiight

[phr2]

Free wifi is going to interfere with military radar, but I bet when some big-money corporate interest group wants those same frequencies, they will get them with no radar objections being raised. We don't hear about UHF television interfering with radar either, or 1.8 ghz cell phones, etc. This is just another scam on the goverment's part to interfere with private communications.

Stupid

[afidel]

The UNI-II band (the unliscensed but regulated chunk of spectrum located around 5GHz) has been set aside for quite some time and the devices have limits that put their power at such low levels that they should not interfere with any existing users of the space. In fact most 802.11a devices have connection ranges well under 100', if the power is so low that they can't even communicate much past 80-100' how can they possibly interfere with multi hundred or thousand watt radar installations, especially when those installations are almost all looking up? Besides if they cut off the consumer bands they lose a source of cheap communications gear that allows them to spend money elsewhere. For instance we supplied large amount of gear free to the national guard for use on 9/12 and the weeks following the tradgedy. This equipment was extremely usefull because almost all of the existing infastructure was ruined because it had been on the fallen towers or relied on facilities that had been in them.

Re:802.11 and police radar

[Izang]

Jamming is a delicate science.

You can tell, by the tone, if a car is reflecting or emitting a signal. There are a few officers like to listen to the doppler shift and it's easy for them to tell if you're jamming. I should know, I was stopped in West Virginia for having one on my motorcycle. Small, low power but since I had access to a radar gun I knew that it kinda worked. I was lucky he couldn't find it wedged way down behind the faring.

The reflected signal off a car is extremely weak so it doesn't take much power to screw with radar. If you really want to have fun put a fish finder in your car and mount the transmitter/receiver on the grill. Something high powered like that will make a radar gun totally useless.

We must not have!

[wiredog]

A mineshaft gap!

If I were a Rogue State...

[wynlyndd]

...Reading this article would make me want to encourage WiFi usage in my country in case the US came a knockin'.

"sorry your radar doesn't work as well as you wanted."

The military is complaining about US use of spectrum that is used by civilians worldwide. Seems they'd have to deal with those issues when dealing with other parts of the world so they might as jolly well deal with it here.

Re:Other problems as well

[Detritus]

It's part of standard industrial safety procedures not to use two-way radios in areas with flammable or explosive atmospheres. The radio can directly or indirectly produce a spark. There are specially designed and certified radios that can be safely used in a flammable or explosive atmosphere. Your cell phone is not one of them.

Yep, that's the obvious point.

[twitter]

Killing the utility of 802.11 in the US won't keep others from expoiting our problems. It will simply keep us from having better, lower cost communications. I posted this making fun of DoD in another thread.

Oh, great...

[TheSHAD0W]

Sure, tell EVERYONE what radio frequencies they need to use to jam US military radar. Sheesh.

Au Contraire ...

[fygment]

... _we_ should worry about interference. As a naval elec officer I recall we had to shut down our radars before coming into the harbour because they wrought havoc with the digital phone switching systems in the area. Wireless users arise and get the military to shut down their PRON interference systems!

Using ISM Bands

[CutterDeke]

Wireless communications devices like WiFi equipment use ISM (Industrial, Scientific and Medical) frequencies set aside for unlicensed usage. Many devices emit in these frequencies. Why is the military targeting wireless LAN applications?

Seems that the military should have taken this into account in the original specs of their equipment.

silly army

[Coward Anonymous]

so all it takes to shut down the U.S. military is a couple Wi-Fi transmitters?
I would hope the military would be able to cope with substantially more intereference than a lowly Wi-Fi access point. Otherwise, they might as well turn out the lights.

microwave desert.

[twitter]

show up as an unknown emitter which in a time of war will generally cause the ship/plane/helicopter to go "defensive" and defend against the potential threat!

So, one $10 wifi card can be traded for one $10,000,000 radar seaking misile? Oh dear, that's worse than hitting a camel in the butt next to an empty tent. What's that myserious uptick in demand for 802.11? Why is it that portions of "no fly zones" are starting to look like New York? Ahhhh!

Me thinks the DoD had better get smarter than that. Shutting down wifi in the US will not keep others from exploiting this problem.

Re:This is still about fighting "terrorists"

[Catbeller]

Osama bin Laden does not use beepers, landlines, telephones, cell phones, WiFi, the Internet, laser comm, satellite phones, carrier pigeons, or the U.S. mail.

He communicates via trusted lieutenants, face to face.

The idea of terrorists using the Internet and WiFi in particular is not only speculative, it's just plain wrong. A professional guerilla warrior does not use traceable tech, not if they want to succeed.

This is FUD. And a prelude to a marketing campaign against free networks. Or, it just illustrates the really bad thinking coming from the White House's Nixon retreads right now -- not Bush. Bush doesn't know WiFi from HiFi. This is coming from the army of Marching Morons that are running the Executive Branch and the DoD right now, to the dismay of the intelligent professionals who have been shoved aside and told to shut up.

err, try again.

[twitter]

better fix the guns

MOD PARENT UP

[goombah99]

that all just mod the parent up

I never thought I would see the day /. and .gov

[t0qer]

would be barebacked doin the nasty sleepin in bed together. I think slash has fallen to an all new low.

We all know GWB and his little gang of croonies have been silently moving to gain "control" over the internet. They've enlisted the help of the RIAA and MPAA plus their teams of lawers to overpower the routers of major backbone providers with threats of bankrupcy. Those that play ball such as AT&T will have their right of way taxes deferred, those like worlcom will have to suffer.

They want it controlled for "our safety" "We don't want no stinkin terrorist using "Our network" to transmit dirty messages to bad 'ol osama (read satan)

They want it controlled to keep the ever slipping grip of media copyright back in the hands of the huge players like sony, virgin, capitol records, ect. Who cares if it hurts the smaller labels.

And killing 802.11 would be a major win to them because it's such a "pirate radio station" They can't control it and that scares them. The worst thing is seeing slash become party to the "psychological warfare and FUD" the .gov is trying to spread about 802.11

I can't really comment about the technical aspects of if this REALLY affects radar, but as an american citizen watching this issue, I can.

A smart person would look at thier reasons and say, "Hmm, messages, oh yeah, PGP mail... and uh people trading MP3, well can't do much there unless you cut off their ears"

Instead of letting the smart people address this issue they're trying to play on our emotions and get the mob riled up. You are not a good american if you run a public 802.11 node. You are not patriotic for sharing MP3's. You're in bed with the terrorist for using encrypted e-mail.

Well, this message too will probably be modded into oblivion too. As i'm sure /. has been given it's walking papers by the man. Either convince your .5 million readers we're right or we pull the plug. Fucking shameful, just shameful.

Let me see....

[Newer Guy]

This would be the same military radar that wipes out most of the FM stations' 950 Mhz Studio transmitter links in San Francisco when ships sail into the harbor and forget to turn it off? Or would this be the same military that insured the U.S. would have a second class digital radio service with no additional station possibilities for the next 50 years. Or is it the same military radio that operates between TV channels 4 and 5 and wipes both of them out part of the time. No wait...I remember now...it's the military that opeates wherever they want to WHENEVER they want to! That doesn't have to comply with FCC regulations like the rest of us. That could gie a f**k who they wipe out in the process of doing their thing....even if it causes their citizens' cancer (ever hear of 'PAVE PAWS"?). THAT military! This 'land grab' our Govt. is doing in the name of 'fighting terrorism' is beginning to both piss me off and scare me............

Take it from a Navy Radar Operator...

[GeekZilla]

...there is more risk to the WiFi networks being jammed by military radar than the other way around. The newest radar's pump out hundreds to thousands to millions of watts of power depending on the type of radar and the platform. Plus, today's military radar's are frequency agile and extremely adaptable to interference and jamming. This appears to be just another attempt by the DOD/DOJ/Big Brother Government to control things that they feel are a threat to their control.

Re:Take it from a Navy Radar Operator...

[Genady]

So what you're saying is that you fried your CO's cool new iBook with the SPY-1D 'eh? Serves him right for leaving the damned AirPort card on in his cabin.

It goes even deeper then that!

[Newer Guy]

Have you seen the ads on TV: "This is Mary. This is Mary's nickel bag of Pot. This is Mary's dealer. This is Osama binLaden. Mary's dealer buys his quarter pounds from Osama." The govt. is trying to connect EVERYTHING to terrorism! They want control over EVERYTHING...and they're doing it in the name of 'protecting' us! The propoganda machine is running full tilt 24/7.......

Re:It goes even deeper then that!

[t0qer]

You think those are a laugh!

The other night i'm watching midnight run on toonami. TOONAMI! and John ashcroft comes on.

He starts telling how patriotic americans all over are taking these "Homeland Security" Courses and goes on to explain how there's a great future in homeland security

Fade Transition

Shows 2 guys with shit eating grins in security guard outfits.

So now instead of giving schools money to teach kids how to program, build networks, and cool shit like that they want everyone to be a rent-a-pig.

I liked it better when our president got blowjobs from his intern and anyone that could click start>run>Microsoft Frontpage was a webmaster.

GWB sucks.

Re:It goes even deeper then that!

[Alien Being]

Not much different than the way Hitler gained power after the Reichstag burned.

Where's John Hinckley when we need him?

um, wrong

[kin_korn_karn]

If 802.11b gear ever starts picking up the same frequencies used by radars, then it's the network stuff that is going to be in trouble, not the radars. The radars are much more powerful emitters than the network stuff could ever think of being.

One thing to keep in mind

[DonFinch]

A wifi emmitter operating in the 5ghz band could potentially draw attention from a HARM anti radiation missile...of course if it slams a laptop/cell phone/pda/SUV yuppie type, I wouldnt be sure if this would be a tragedy or a victory...

Re:Other problems as well

[mesocyclone]

The problem isn't "high-speed tower-hopping."

The problem is that the signal from one cell phone at altitude hits many cell towers at once, interfering with other callers.

The word "cellular" means that the system uses small areas called cells. The primary reason for for this article is to allow the same frequencies to be used in multiple separate cells at the same time, by different users. From an airplane, all of those cells are hit at once.

Cellular architecture is one method of improving spectrum efficiency, and was mandated by the FCC for that reason.

Re:...a Beowulf cluster of these!

[coreman]

I couldn't resist :)

They're giving ideas to terrorists

[RickyRay]

By announcing to the whole world that they can't deal properly with ordinary WiFi, the military is encouraging terrorists to interfere in those frequency ranges. Which means terrorists and military regimes could buy cheap, off-the-shelf WiFi, amplify the signal to make sure it gets noticed (if it's strong enough it could even interfere), and scatter the transmitters all over the place to keep the military busy tracking down ghosts.

A friend of mine (just as an experiment; I wasn't involved) once tried driving down the road with a box that repeated speed detector signals back to cops with a slight frequency shift (to mimic the Doppler effect) and amplified (to block the correct signal). His speed was legal, but the cop started banging on the speed detector because it either said he was going really slow or insanely fast (exaggerated enough that it couldn't possibly be correct). Needless to say, you can't buy such a box legally ;-)

Could your WAP get WACKED by a HARM?

[LWATCDR]

That could get pretty ugly. Or perhaps an EA-6b could fry your ibook :)

Re:802.11 and police radar

[LWATCDR]

Umm... A fish finder???? That is sonar not radar.

More Nonsense from DoD

[blate]

Doesn't Wi-Fi run on an "unregulated" frequency, as specified by the FCC? This means that any device using this spectrum must accept interference from other devices in this spectrum, such as microwaves and cordless phones.

This seems like a thinly-veiled attempt to limit personal freedom and access to the internet, IMHO. If the millitary is using radar in these spectra, that's their fault; they must deal with it and not blame their ineptitude on the wireless internet community.

Re:More Nonsense from DoD

[ainsoph]

yup...

How about radio astronomy?

[infolib]

I remember my first term physics professor when a cell phone once rang during lecture:
"If this goes on, every form of radio astronomy will soon be absolutely impossible"

The coolest reaction to annoying cell phones I ever heard.

Re:Other problems as well

[aborchers]

Thanks for the clarification. I thought hard about that post because I knew I wasn't correctly expressing the nature of the problem, but in the end laziness won out and I hit "Submit" anyway.

So I might be paranoid but...

[Maudib]

Could it be that the DOD just considers a widespread decentralized highspeed wireless network a threat?

Its one thing if the network is owned by a large corporation that can be dealt with easily by the dod. But as a lot of WiFi is community based, a widespread network would be harder to control or shutdown. Making 3g attractive to the DOD as their lawyers can mandate the tapping of someones account or even shut the network down in a region. But Community WiFi has no such centralized authority that can be targeted.

WI-FI is spread spectrum, radar is AM

[Anonymous Coward]

It is impossible for WI-FI to interfere with radar because of the simple fact that spread-spectrum modulation spreads the energy over a wide band and turns the signal into an extremely small amplitude wide-band energy that will not even be seen by a radar receiver looking for pulses in the time domain. Spread spectrum is in the code domain. WI-FI will not interfere with radar and radar will not interfere with WI-FI. The radar receiver's noise floor will be higher than any WI-FI spreaded signal. If the WI-FI adapter gets so close to the radar that it can interfere, it would have long since burned up from the Megawatt radiated pulses from the radar.
This is typical exagerated government BULL SHIT.

Re:802.11 and police radar

[Izang]

I'm just telling what I have seen. An 8000W fish finder, maybe 200khz, will totally screw a radar gun. My ex-brother-in-law was a cop and we've tested it right out of the boat.

Re:Other problems as well

[krlynch]

It isn't that the industry doesn't want to deal with the problem (although they don't want to, they have to anyway, since lots of people just leave their cellphones on in the air already), but that there just isn't the necessary capacity in the SPECTRUM to deal with the problem.

In any location that is within range of more than one cell tower, each tower has to use a non-intersecting set of frequencies for data transmission. If all the phones are on the ground, that isn't so much of a problem (but it is getting to be due to network usage); you generally only see a few towers at a time (line of sight interference by buildings, hills, dips in the road, etc.), and non-adjacent cells that are nearby can get away with reusing frequencies. In the air, the number of cells you can see is much larger (no line of sight interference, and a much larger distance to the horizon). To "deal with the problem" you would have to prevent frequency reuse even in NONADJACENT cells, over a very wide geographic area, in order to allow airborne cell phone use. Given current network utilization, future capacity needs, and allocated spectrum, there just aren't enough frequencies to parcel out.

The solution to the capacity problem on the ground is to put in more towers that provide coverage to a smaller piece of real estate. But doing so makes the airborne problem even worse.

How about UWB 802.11?

[JohnnyCannuk]

Sounds like a good time to switch to/invest in a new 802.11x ultra-wide-band solution.

UWB, as I understand it, sends out nano-second pulses over a wide band of frequencies. These pulses sound like regular "noise" if they are detectable at all. Best part they don't interfere with existing signals on any particular frequency. They can be used for communications or specialized radar (ground penetrating, seeing through walls to find people etc).

So either your DOD swithces it's radar or gets your FCc to allow higher power UWB (currently the range is limited to about 10 meters...great for a UWB mesh network ;) )

Anyway, I may not be the most knowledgable in the field, so someone ca correct me but this sounds like a great opportunity to make a better more decentralized technology take hold

Re:Hardly...

[Sabalon]

So, my 2.4Ghz wifi AP and my 2.4Ghz baby monitor and phone and microwave all interfer with each other.

Now, while they all need to accept any harmful interference, they should not generate any harmful equipment...so data should not cause popping on the baby monitor, neither should warming water in the microwave.

Oh dear...my house is full of violations

WRONG WRONG WRONG!!! (bzzzzt)

[flatulus]

There is so much misinformation in both the NY Times article and the discussion here on /., I just have to set the record straight:

1) The DoD is concerned about the 5 GHz U-NII (Unlicensed National Information Infrastructure) band -- which is where 802.11a (not 802.11b) operates. This is a recently opened band.

2) There is no way the DoD can mount a plausible objection to 802.11b, as it operates in the 2.4 GHz ISM (Industrial, Scientific, and Medical) band. The ISM band is the home to microwave ovens, which frequently "leak" 30 times more RF than an 802.11b "intentionally" transmits. There are industrial applications of the 2.4 GHz ISM band that emit KILOWATTS of RF. The 2.4 GHz band is, in essence, the junkyard of the microwave spectrum.

3) The IEEE 802.11 committee is already working on interference mitigation techniques to make 802.11 radios more "friendly" to radar in the 5 GHz band. This is the work of Task Group H. The two major innovations being hammered out in that task group are DFS and TPC (dynamic frequency selection and transmit power control). Both of these are mandated by the European Union's regulatory bodies, in order to open up 5 GHz for 802.11 radios. When ratified, this will lead to an 802.11h radio, which is functionally analogous to 802.11a, but with DFS and TPC. At that time it is likely that 802.11a will wither on the vine, being replaced with 802.11h in the U.S. also. (Note: 802.11a is legal only in the U.S. today. And DoD is basically following the EU's lead in expressing concern about interference to radar. That's what the NYT article meant about Europe being "ahead" in this matter.)

4) While the FCC is in charge of CIVILIAN use of the RF spectrum, they are not the sole arbiter of RF in the United States. The rest of the job is done by the NTIA (National Telecommunications and Information Administration), which is the caretaker for government use of spectrum. For the FCC to open up the 5 GHz spectrum, they needed approval from the NTIA first (which they got).

Summary: "But the times they are a' changin."

Basically the DoD is trying to head off proliferation of 802.11a before it's too late. Of course, the market leading vendors (e.g. Atheros) are none too happy about this, and I don't blame them. Changing the rules after they invest many millions in development of a product on the basis of an expectation of marketability would make even the most accommodating entrepreneur cranky :)

802.11 range

[Eric Green]

Check out this new antenna design that supposedly gives 802.11 a three-mile range.

DoD FUD

[markcic]

This is FUD generated by the DOD. The FCC limits the EIRP (equivalent isotropically radiated power) of the ISM band used by 802.11. The allowable power levels for 802.11 are 1 watt using an omni-directional antenna and 4 watts for a directional antenna. I doubt the tinny amount of power these devices emitted will interfere with military radar. For more info about 802.11 power levels check out this 802.11 Planet article.

how is this flamebait?

[commodoresloat]

I don't necessarily agree with the author but he's making a valid point, even if his name is stinky wizzletits.

Re:read between the lines...

[zogger]

--I agree. Read the whole thread down to here, see nothing but as you suggest-the dotgov is more scared of anonymous civilian communications than interference. It was also my first impression at the top of the thread and when I read about their concerns about wifi helping the terrosists. They want to try and get the "little guy" communications jenni back in the bottle as much as possible. the wired internet they can control at the main backbones, it just wouldn't take that may people to show up and start to flip switches. the broadcast commercial media they can takeover automatically with the FEMA command and control boxes they have installed all over. Next step for them is to try and come up with a way to control personal radios of various kinds, including wifi.

How many times do I have to say this...?

[cr0sh]

I have read many of the comments made on this topice here in this forum. I understand that there seems to be a confusion as to whether this issue is related to 802.11a or 802.11b. Frankly, I don't think it matters.

The fact is, 802.11x communication systems ARE REGULATED BY THE FCC. If they chose (or were ordered), they could easily deem the spectrum used by 802.11x to be off-limits to anyone! Sure, I have heard the comments like "but businesses have invested millions in 802.11 - they would howl" - perhaps they might. Or perhaps a transition would occur to make the larger companies happy, by providing some form of wireless that isn't available to the average consumer like 802.11x is - but still gives those communications companies a foothold in wireless comms, while making consumers happy, and also possibly providing an easy place for the feds to tap, while making community nets a thing of the past (think it impossible? Try to buy, as a consumer, your own TXRX system for a cell phone - good luck, if you can even afford it). Everyone (mostly) wins - except for the citizen, ne - consumer...

I have said many times that the government has this (unelected, unrepresented) power via the FCC to do this (think I am joking? Do a search on my past comments, if you don't believe me). In these same comments, I have presented a solution that very few have worked on (at least on the homebrew front), that could keep community networks alive, a solution the government (FCC) cannot regulate (but oh how they would try - and if they succeeded, well - then that is the cue for true revolution):

Laser/LEDComm

I daresay RONJA is probably the most advanced "homebrew" system out there (if anyone has links to more advanced stuff - such as on the order of homebrew sighting/retargeting systems like AirFiber's System - please post links!). Other links of interest:

http://www.alphalink.com.au/~derekw/upn tcvr.htm

http://www.hut.fi/Misc/Electronics/circu its/laserlink.html

http://www.geocities.com/Silic onValley/Lakes/7156/laser.htm

http://www.n1bug.ne t/tech/laser/laserfr.html

http://www.n1bug.net/te ch/laser/alc_wa6ejo.html

http://www.repairfaq.org /sam/lasersam.htm

http://www.qsl.net/w1vlf/techin fo/optical_transmitters.html

http://misty.com/peo ple/don/laserdon.html

So - these systems have problems (line of sight being the largest) - but all systems have problems. At least one company (AirFiber) is using similar tech to run a business for WAN layouts - so it should be possible for a homebrew solution to be worked out. Are we going to simply wait until 802.11x really gets "outlawed" before we do something? What kind of shit is that?

Oh - wait - this is /. - where apathy seems to almost be the rule when it comes to politics...

Markoff has been wrong before

[neitzert]

Markoff has been wrong as many times as he has been right. A post on BAWUG suggested that this was an urban myth -- case in point being: what did the DOD do when all of their microwave communication ran on 2.4ghz back before wifi was even a pipe-dream?

Markoff is such a tool, have you read his books on Mitnick -- what a joke.

What a load of shit and here is why

[codepunk]

Man I spent 10 years in the navy as a Operations Specialist. Besides fragging ragheads with tomahawks my other job was to watch a radar screen all day. If you think for a second that a measly half watt signal 5 miles away is going to screw with a ageis phased array radar you are a bigger idiot then the people writing these articles. The radar systems are severly hardened against interference both natural and some towel head trying to jam you by pushing a million watts at you splattering the entire band. Now think about it, is your little Proxim card going to jam or interfere with my million watt ship radar...ROTFLMAO

Hell I am not even going to get into the frequency hopping shit

Re:What a load of shit and here is why

[ainsoph]

Besides fragging ragheads with tomahawks.

U are one moronic peice of shit. How does it feel for ya?

Re:What a load of shit and here is why

[ainsoph]

Oh and by the way, stupidprick.com, where the fuck do you get off calling people "ragheads"?

Just a question... Prick..

Rules for intercepting NORDO/hijacked aircraft...

[Robber Baron]

...can be found here. Note that they don't say a goddamn thing about requiring presidential approval.

"Well, the--I suppose the toughest decision was this question of whether or not we would intercept incoming commercial aircraft...Yes. The president made the decision...that if the plane would not divert...as a last resort, our pilots were authorized to take them out. Now, people say, you know, that's a horrendous decision to make. Well, it is. You've got an airplane full of American citizens, civilians, captured by...terrorists, headed and are you going to, in fact, shoot it down, obviously, and kill all those Americans on board...It's a presidential-level decision, and the president made, I think, exactly the right call in this case, to say, "I wished we'd had combat air patrol up over New York."" - Dick Cheney

Spot the lying bastard.

errrrmmm...

[GC]

bit late for this isn't it?

Submit your proposal as an RFC?

Re:This is still about fighting "terrorists"

[ces]

This is why you should run VPN tunnels across the wireless segement. If you have a firewall between the WAP and the wired network you can prevent anyone without valid VPN authentication from accessing the wired side of the network.

Admittedly this isn't really "securing" the wireless network but piggybacking other security technologies.

Cell phones and stealth aircraft

[jabber01]

Not so long ago, we all found out that the multi-billion dollar stealth aircraft that is the pride and joy of the US Air Force can be detected with cell phones.

Now WiFi jams military RADAR? What's next? Toasters cause bullets to malfunction? The beige of PC cases gets banned because soldiers in OD greens can't blend in in a server room?

Until the military says they want to ban cell phones, I'm going to be skeptical of any ban of WiFi technology at large.

Re:RIGHT! RIGHT! RIGHT!!! (ding!)

[anticypher]

This pentagon group isn't really looking out directly for the U.S. military, they're a pressure group for the big (lock-mart, boing, et.al.) defence contractors who want that spectrum for themselves for cheap.

The U.S. is sending a large delegation to the WARC (world administrative radio conference) in June/July of 2003, to argue with all the other delegates about, well, everything (amateur bands, satellites, modulation schemes, software radio, digital TV, maritime, aeronautique). This U.S. pressure group is trying to make sure the U.S. delegation fights to ensure the 5GHz band doesn't get given up to the public for free. They want the delegation to try to defeat the move for another globally accepted chunk of spectrum for low cost commercial products.

The meeting was with the main U.S. commercial groups making a fortune off of 802.11b kit(aetheros, intersil, TI, intel), in order to convince them they would be un-patriotic if they try to duplicate the only bright spot in the electronics world today in another small chunk of the spectrum. This in the face of reality of 802.11a products already on the market.

This is old school thinking, to try and preserve the scarcity of the spectrum, because another small "free" section would "cheapen" property values in the spectral neighborhood. Better to keep as much spectrum out of the hands of the public, in order to keep the value sky-high.

The Europeans are getting their act together through the ETSI, and telling each national government to clear out all military and commercial users from the 5GHz 802.11h band. They've been studying this for at least the last two years, and finding very little in the band that isn't easily moved. There are no fixed military radar systems using that part of the 5GHz band, but some agile systems may sweep through it.

802.11a may never be allowed in Europe, and given the speed *ahem* working group H is proceeding, the first 802.11h kit might be available soon after WARC. Of course, h kit is much more complex than a kit, meaning longer times to market, more expensive, and lots of interop problems are going to be seen between chipsets. But the DFS/TPC features will mean many more 802.11h products can co-exist in dense city centres, where it counts. The american chip designers placed their bets on getting 802.11a to market faster with a less capable product in the hopes grabbing the lions share.

When the rest of the world starts using 802.11h for all kinds of shiny cool toys, the U.S. may outlaw it in the name of national defence. That would be sad, but typical.

This next WARC meeting should be as interesting (in the chinese sense) as the previous ones. Think "a more wretched hive of scum and villainy has never been seen on this planet".

the AC

If Clinton had been president

[MichaelPenne]

more likely he would have acted on his plan to attack Al Qaeda:

The Bush administration sat on a Clinton-era plan to attack al-Qaida in Afghanistan for eight months because of political hostility to the outgoing president and competing priorities, it was reported yesterday.

Rather than sit on it.

Meanwhile, Clinton, with the Legislature spending most of their time sniffing blue dresses for presidental spunk, lacked the support necessary to invade Afghanistan and take out Bin Laden.

Bush's team thus has two major mistakes to answer for: not listening when Berger and Mr Clarke outlined the threat in briefings they provided for Condoleezza Rice and, when they did get around to taking action, letting Bin Laden escape.

However, I agree that one can't really fault Bush for not giving the order to blow civilian airliners out of the sky on 9/11, I don't think even Jack Ryan would have been that on the ball.

Re:Rules for intercepting NORDO/hijacked aircraft.

[duffbeer703]

"Interception" does not mean shooting down an aircraft.

An interception is when an aircraft makes visual contact with the aircraft in order to ascertain it's situation. Often the pilots will communicate via hand gestures or signs.

Until around 11 AM September 11th, any non-defensive attack against an aircraft or sea target in US territory had to be authorized by the president.

Today, a local theatre commander or duty air operations officer can make the call.

Um....

[MacAndrew]

I hope this is not perversely seen as a troll; if anything my tone is more moderate than that of many others.

I'm not a fan of President Bush, although I do respect the office. I do not believe most of the 9/11 rumors I have heard because on closer examination they are as thin as typical conspiracy theories. Finally, and most importantly, I live 3 miles from the Pentagon and saw the airplane pass overhead at about 500 feet and crash and explode. I want to know every last detail of what happened and do not give a damn who it may embarrass.

But that's not possible, not even by half. Why do we still not have a 9/11 commission? The wisdom is there: gov't simply does better with independent auditors. The precedent is there: commissions were appointed for the Oklahoma City bombing, the Kennedy assassination, even the Challenger tragedy, in a fraction the time. And the opportunity is ... passing.

The administration has barely attempted to justify the delay. The only justification I can think of is national security, but have heard no details, or any reason the commission should not have been collecting data and testimony on nonsensitive topics. The trail is growing cold.

If you want to fault the administration on something, hold off on the conjecture and focus on the concrete. The commission question we have front and center is compelling. Sure I have various suspicions, but we don't even have a commission report to beat up on!

I hope the commission is a good nonpartisan issue that will move forward. Choosing Henry Kissinger to start was ... um ... counterintuitive and wasted even more time. I know it's trite, but "Let's roll."

Re: Your Sig ...

[rnturn]

OOLCAY ITAY

;-)

Re:Rules for intercepting NORDO/hijacked aircraft.

[Robber Baron]

Maybe I should've used the word "obfuscating" instead of "lying".

The fact is, contrary to established procedure, they didn't even attempt to intercept...that is go take a look and try to find out what the hell was going on.

health effects of 802.11?

[haaz]

I am seriously looking for information on the health effects of 802.11 as used in a large public area. Specifically I want to know if it makes people sick. Does the radiation from the 802.11 cause health problems? And what sort of radiation is it? Microwave? Radio?

I know this may sound crazy to some, but let's look at it carefully. I do need to know this for future projects I'm thinking of starting, such as true public WLANs. thanks!

ps - contact me if you have good information.

Re:Rules for intercepting NORDO/hijacked aircraft.

[duffbeer703]

Yes, they did.

The nearest fighter aircraft was stationed in Massachusetts (Andover AFB i think) and was at Ready-30 status since we are not at war and budget cuts removed fueled interceptors from the flightline.

Therefore it took 30 minutes to launch the plane once the order was received, and another 35 minutes to reach the hijacked plane. The fighters would have had to intercept the airliners at least 50 miles from the city.

Re:Hardly...

[Skuld-Chan]

What that means os if all your devices are causing interference to me - a licensed amateur radio operators I can request that the FCC send you a letter telling you that you need to do something about the interference.

And since Amateur radio operators are primary users on 2.4 ghz doubly so.