I wonder what kind of interference levels can be expected if some HAM operator did this on 2.4Ghz today? Would the bounced signal be strong enough to cause real interference across a large portion of the globe?
Let's do the math - a.030 watt access point will deliver about -70dBm signal to a wireless card 20 meters away using dipole antennas. The noise floor is usually about -100dBm. The moon is a return trip of approximately 400 million meters, or 20000000 times further away. Signal strength is the inverse square of the distance, or 400000000000000 times weaker. Let's assume we're using a 40db dish (one the FCC would have no trouble noticing in your backyard) and you're transmitting at the full 1500 watts output. The signal is 50000 times stronger and your dish amplifies it another 10000fold. The resulting signal is now only 800000 times (or about 59db) weaker to a non-directional antenna (or a directional antenna not pointing at the sky), resulting in a signal level of -129dBm. Which is significantly weaker than a typical noise floor of about -100dBm. As you can see, amateur radio EME (earth-moon-earth) requires a non-trivial antenna array pointed at the moon to even receive such signals.
Did they arrest the aide for breaking copyright law
IANAL, but people are not arrested for civil copyright infringement - the copyright holder must file a civil suit against the infringer to recover damages. A film company wouldn't sue Feinstein's aide, that's ridiculous.
Take a careful look at the FBI warning thingy on your MPAA-compliant home videos - they don't actually say what criminal copyright infringement is, they just outline the penalties for it. You're left to assume (wrongly) that making a copy of the video or showing the video in public is criminal.
but then they're going to lobby the gummint to give them a monopoly on that "technology" (by applying for a patent).
I haven't looked at the patent application, but there's all sorts of prior art in this field. Most notably, APRS. I wouldn't write off interoperability so soon. Besides, the patent wouldn't make Garmin much money if they can't license it. It's not like there's much consumer demand for features that only one vendor has any hope of providing.
Does this specify who gets your location, or can anyone on that freq see that quantumRiff is standing in the bathroom??
The FCC does not allow encryption on Family Radio Service bands (47CFR95.183(a)4) They usually don't allow data either - Garmin had to get the FCC to make a specific exception for the Rino.
Exactly WHAT is an agency of the US Gov going to crack that will allow it to gain exactly WHAT money to amortize it's $1B that won't be missed?
If you've been properly trained in US politics, the phrases "Won't someone please think of the children" and "National Security" should pop into your head immediately.
Why are we worrying about one billion dollars when having the capability to factor 1024-bit RSA keys could save children's lives?!
What it boils down to is that the government does not have the right to make any laws that infringe speech. They just have the right to make laws that promote the progress of science and the useful arts. If they can't do this without infringing speech, they have to go back to the drawing board.
Light consists of waves, and when two waves are placed on top of each other, they form a new wave that takes no more space or bandwidth than the first one.
Just like when I XOR two streams of data together they take no more space than one stream? Kind of tough to pick that apart again./dev/null doesn't get any bigger when I throw a stream of data in it either.
Assuming the waves are assembled constructively, receiving them in the same bandwidth requires double the signal/noise ratio that receiving one wave would require, because your equipment needs to be just as sensitive but handle twice the signal amplitude. See Shannon's Law.
i'd still like to know where this dude's car is parked that it gets 158 F inside the car in the summer time... you could fry eggs on the dash!
Anywhere in the continental US, for starters. Because of the greenhouse effect, a car parked in direct sunlight can reach over 200 F inside, even if it's only 70 F outside. That's why you're not supposed to leave kids or pets inside cars unattended.
At which point your users finally found a password that the system would allow them to use, and, bitter and pissed off, wrote it on a Post-It(TM) note and stuck it to their monitor.
Nah, they knew better than that. They'd put the post-it note underneath the keyboard.
It has to take someone longer than 30 seconds to memorize it if they were to see it written down somewhere
It has to take me less than 2 seconds to type it in
Any password that fits this criteria will take a long time to crack and even longer to figure out by looking over someone's shoulder.
ObTrivia: at a place I used to work, 246 out of 780 user accounts had a password of "", "pass", or "password". Before I convinced the IT director to let me implement strong passwords, anyway.
UNIX: Everything is a file
Windows: Everything is an object
I guess it all comes down to whether they can make the surrounding environment rich enough that people can do everything they can do with objects as easily as they can with files (without writing a program).
For example, if you (the reader, not the article poster) work in a smaller shop where the servers are always getting cannabalized, you could go with Donner Party members:
Backenstoe
Breen
Burger
Denton
Dolan
Donner
Eddy
Elliot
Fosdick
Foster
Graves
Halloran
Handley
Hardkoop
Henderson
Herron
Hook
James
Keseberg
Keyes
McCutchen
Miller
Murphy
Pike
Reinhardt
Reed
Snyder
Spitzer
Stanton
Trudeau
Williams
Wolfinger
Zimmerman
Those four elements you see in the top picture would each be 3.5" long. You could call them "ugly sticks", because there's no way you could conceal more than two of them in a cell phone's case.
If the incoming wave and the antenna have the same polarizations, and the antenna is "perpendicular" to the incoming wave, you'll actually get 0 signal. You want the antenna to be "parallel".
In theory, yes, in empty space one can get over 30db of signal discrimination by choosing the opposite polarization - in practice however, the signal bounces all over everything between your cellphone and the tower, so signals of all polarization get through. Otherwise you'd instantly drop calls every time you held your phone horizontally or pointed your phone's dipole directly at the tower (assuming your phone could only reach one tower).
Cellphone towers are all vertically polarized (almost all amateur and business-band radio is as well). Broadcast TV/radio is horizontally polarized.
Re:And how are they supposed to measure this?
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They even have this absolutely !!!HUGE!!! TV billboard
The one near Fife? I wouldn't mind seeing more paintballs splattered across that thing.
Third, according to the ARRL antenna handbook, the 200" optical receiving antenna known as "Mt. Palomar" has 148db gain. Frankly, I don't think anyone's satellite dish compares to this (or could, at microwave frequencies)
Remember, 100db gain means 10 million watts of effective radiated power for every milliwatt of input power.
Antennas with over 30db of gain simply are not that common.
as you walk through a detector arch, the computer identifies and deactivates each tag it senses.
So if a person in a mall walks up to an item with a homebrew pocket RFID transceiver which accepts payments (into/dev/null), that person is then free to leave the store with goods in hand?
To avoid suspicion, it wouldn't even have to be carried out of the store on the same day or even by the same person.
Even video camera surveillance could be defeated as long as people trust such a system - for example, to remove a sweater from the store, wear modest clothing, just pick up two already-paid-for sweaters off the rack (a little slight-of-hand to make it look like you're just taking one helps), go into the changing room, put one of the sweaters underneath what you were wearing, return the other one to the shelf, perhaps buy something else, and walk out the store wearing the paid-for sweater.
That depends on a lot. If the maximum voltage you can put over the twisted pair is regulated by the FCC, then yes, you'll be able to push a signal farther down the coax.
Meanwhile, the telephone companies have been running long haul T1 links for decades.
Slashdot Mirror
I think the DBEDEWX references are getting a little old...
Is it my breath today?
Let's do the math - a .030 watt access point will deliver about -70dBm signal to a wireless card 20 meters away using dipole antennas. The noise floor is usually about -100dBm. The moon is a return trip of approximately 400 million meters, or 20000000 times further away. Signal strength is the inverse square of the distance, or 400000000000000 times weaker. Let's assume we're using a 40db dish (one the FCC would have no trouble noticing in your backyard) and you're transmitting at the full 1500 watts output. The signal is 50000 times stronger and your dish amplifies it another 10000fold. The resulting signal is now only 800000 times (or about 59db) weaker to a non-directional antenna (or a directional antenna not pointing at the sky), resulting in a signal level of -129dBm. Which is significantly weaker than a typical noise floor of about -100dBm. As you can see, amateur radio EME (earth-moon-earth) requires a non-trivial antenna array pointed at the moon to even receive such signals.
IANAL, but people are not arrested for civil copyright infringement - the copyright holder must file a civil suit against the infringer to recover damages. A film company wouldn't sue Feinstein's aide, that's ridiculous.
Take a careful look at the FBI warning thingy on your MPAA-compliant home videos - they don't actually say what criminal copyright infringement is, they just outline the penalties for it. You're left to assume (wrongly) that making a copy of the video or showing the video in public is criminal.
I haven't looked at the patent application, but there's all sorts of prior art in this field. Most notably, APRS. I wouldn't write off interoperability so soon. Besides, the patent wouldn't make Garmin much money if they can't license it. It's not like there's much consumer demand for features that only one vendor has any hope of providing.
The FCC does not allow encryption on Family Radio Service bands (47CFR95.183(a)4) They usually don't allow data either - Garmin had to get the FCC to make a specific exception for the Rino.
Anyone can listen in.
If you've been properly trained in US politics, the phrases "Won't someone please think of the children" and "National Security" should pop into your head immediately.
Why are we worrying about one billion dollars when having the capability to factor 1024-bit RSA keys could save children's lives?!
Fair use is free speech, Congress does not have the right to take it away.
What it boils down to is that the government does not have the right to make any laws that infringe speech. They just have the right to make laws that promote the progress of science and the useful arts. If they can't do this without infringing speech, they have to go back to the drawing board.
Just like when I XOR two streams of data together they take no more space than one stream? Kind of tough to pick that apart again. /dev/null doesn't get any bigger when I throw a stream of data in it either.
Assuming the waves are assembled constructively, receiving them in the same bandwidth requires double the signal/noise ratio that receiving one wave would require, because your equipment needs to be just as sensitive but handle twice the signal amplitude. See Shannon's Law.
Anywhere in the continental US, for starters. Because of the greenhouse effect, a car parked in direct sunlight can reach over 200 F inside, even if it's only 70 F outside. That's why you're not supposed to leave kids or pets inside cars unattended.
Nah, they knew better than that. They'd put the post-it note underneath the keyboard.
Any password that fits this criteria will take a long time to crack and even longer to figure out by looking over someone's shoulder.
ObTrivia: at a place I used to work, 246 out of 780 user accounts had a password of "", "pass", or "password". Before I convinced the IT director to let me implement strong passwords, anyway.
Windows: Everything is an object
I guess it all comes down to whether they can make the surrounding environment rich enough that people can do everything they can do with objects as easily as they can with files (without writing a program).
I've been told that there's a medical institution in the Seattle area that does this. They actually have a server named ghonorrea.
Backenstoe Breen Burger Denton Dolan Donner Eddy Elliot Fosdick Foster Graves Halloran Handley Hardkoop Henderson Herron Hook James Keseberg Keyes McCutchen Miller Murphy Pike Reinhardt Reed Snyder Spitzer Stanton Trudeau Williams Wolfinger Zimmerman
Very obscure, and has high amusement potential.
The US only had 3 nukes in 1945 and they'd already tested one on their own soil.
They simply didn't have any spares.
That would involve something like a turnstile antenna.
Those four elements you see in the top picture would each be 3.5" long. You could call them "ugly sticks", because there's no way you could conceal more than two of them in a cell phone's case.
If the incoming wave and the antenna have the same polarizations, and the antenna is "perpendicular" to the incoming wave, you'll actually get 0 signal. You want the antenna to be "parallel".
In theory, yes, in empty space one can get over 30db of signal discrimination by choosing the opposite polarization - in practice however, the signal bounces all over everything between your cellphone and the tower, so signals of all polarization get through. Otherwise you'd instantly drop calls every time you held your phone horizontally or pointed your phone's dipole directly at the tower (assuming your phone could only reach one tower).
Cellphone towers are all vertically polarized (almost all amateur and business-band radio is as well). Broadcast TV/radio is horizontally polarized.
The one near Fife? I wouldn't mind seeing more paintballs splattered across that thing.
If it's incandescant, it is on.
Unless you believe that tungsten element flips between cold and white hot with every half sine wave.
Flourescents are a different story.
Watch Dawson's Creek.
Second, people have done the Primestar dish thing before and report 22db gain with it, not 30-50.
Third, according to the ARRL antenna handbook, the 200" optical receiving antenna known as "Mt. Palomar" has 148db gain. Frankly, I don't think anyone's satellite dish compares to this (or could, at microwave frequencies)
Remember, 100db gain means 10 million watts of effective radiated power for every milliwatt of input power.
Antennas with over 30db of gain simply are not that common.
access-list 20 permit [monitoring ip address]
snmp-server community [communityname] RO 20
The access list number, 20, is arbitrary. It's in a range that denotes a simple IP access list.
So if a person in a mall walks up to an item with a homebrew pocket RFID transceiver which accepts payments (into /dev/null), that person is then free to leave the store with goods in hand?
To avoid suspicion, it wouldn't even have to be carried out of the store on the same day or even by the same person.
Even video camera surveillance could be defeated as long as people trust such a system - for example, to remove a sweater from the store, wear modest clothing, just pick up two already-paid-for sweaters off the rack (a little slight-of-hand to make it look like you're just taking one helps), go into the changing room, put one of the sweaters underneath what you were wearing, return the other one to the shelf, perhaps buy something else, and walk out the store wearing the paid-for sweater.
If you can get a digital signal on a CDMA-based cellphone from your basement, you might want to look into this horrifically-overpriced box.
That depends on a lot. If the maximum voltage you can put over the twisted pair is regulated by the FCC, then yes, you'll be able to push a signal farther down the coax.
Meanwhile, the telephone companies have been running long haul T1 links for decades.