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It's more of a grey area than that, FCC Part 15 devices must accept all forms of interference. There is no real recourse. Provided that the device is transmitting within 2.4 or 5.8 GHz band channel size limits and EIRP, it's not illegal to crap up the half duplex medium of Part 15 wifi bands.

Say you live in a wood framed apartment building and your neighbor to the left has a 2.4 GHz wifi AP running a 20 MHz channel on channel 1, your neighbor to the right has another similarly configured AP on channel 6, and your neighbor directly below you has an AP on channel 11. The other neighbors diagonally to you are on channels 3 and 7. The 2.4 GHz spectrum in your apartment is totally shit because you're seeing everyone else's AP at -68 or thereabouts, because it's a wood framed building and they're so close to you, the spectrum is totally crapped up and noisy but it's not "jamming". This script has the same effect on real world data transfer speeds as the effect in a totally normal major urban area "2.4 GHz is shit here because I live in a 65 unit building and every single suite has their own wifi AP".

What this small script is doing has basically the same effect on a particular section of 20/40 MHz wide radio spectrum as if you were to install any ordinary $70 wifi AP in WPA2-PSK mode, put it on your choice of channel, and leave a pair of laptops associated to it running bidirectional iperf tests on a 1-minute cron job continually between each other. Totally legit. It's just making the channel in question "noisy" RF-wise, because wifi radios are a "listen before transmit" (CSMA) half duplex medium.

Where it gets into a grey area is stuff like this:

http://www.cnn.com/2014/10/03/travel/marriott-fcc-wi-fi-fine...

http://money.cnn.com/2015/01/27/technology/fcc-wifi-hotel/

operating a noisy 2.4 or 5.8 GHz shitty thing on your own AP is totally legal. Connecting to other peoples' networks or gear at a layer 2 ethernet level and issuing deauth frames is not, and the FCC can come down on you for it. The difference is that the first (being noisy) is at basically OSI layer 1, you're shitting on the radio spectrum the same way as if you had a non-ethernet-speaking RF noisy baby monitor, but not talking to anybody else's devices by their MAC address, the second is actually an active form of layer 2 ethernet fabric attack (that happens to be conducted via 802.11abgn(ac))

5 comments

Where did you come up with layer 1 v. layer two mattering at all? If you look at the FCC consent decree[1], e.g., §II "Background", ℙ2—"No person shall willfully or maliciously interfere with or cause interference…". There isn't anything about the particular method used mattering.

Presumably, if you set up a pile of 2.4GHz baby monitors because you wanted to take out your neighbor's WiFi, that'd be illegal. So too would the device in the article. (IANAL, and I certainly haven't tried to read all the code & regulations).

That really looks to be essentially "don't be a jerk", codified. If you want to use the spectrum to communicate [within all the limits set by the rules], go ahead. When a bunch of people all want to, it may not work as well. But if you want to use the spectrum to stop others from communicating—stop being a jerk. (You may, of course, substitute stronger words for "jerk").

[1]: https://apps.fcc.gov/edocs_public/attachmatch/DA-14-1444A1.p...

> But if you want to use the spectrum to stop others from communicating—stop being a jerk. (You may, of course, substitute stronger words for "jerk").

I think a big part of it is the corporate entity involved and money involved - they were jamming peoples' HSPA+/LTE-to-wifi hotspots because they wanted to sell $600/day internet service for trade shows and conferences...

It's not that the FCC delineated between layer 1 and 2 in their decree, it's the difference that they intentionally messed with wifi at the wifi-protocol level by issuing deauths, not by being noisy... for example if the hotel had a hundred wifi security cameras, baby monitors and other random part 15 devices in use in their facility, effectively preventing anyone from using wifi because the spectrum was too full of shit, that wouldn't be "jamming", even though it would have the same effect.

In the HAM bands FCC still has some provisions for intent. I.E. if you don't follow a local coordinating band plan the FCC can fine you. Even though they don't have an explicit law for band plans.

I wonder if there's a similar law for the unlicensed bands.

There is nothing grey about it. Read it here: https://www.fcc.gov/general/jammer-enforcement

  Federal law prohibits the operation, marketing, or sale of any type
  of jamming equipment, including devices that interfere with cellular
  and Personal Communication Services (PCS), police radar, Global
  Positioning Systems (GPS), and wireless networking services (Wi-Fi).

If you use the device in this story to jam Wi-Fi you're a felon and the FCC will seize your equipment, bury you in fines and/or put you in prison. The "accepting interference" requirement does not immunize anyone from prosecution for jamming. Unlicensed != unregulated, and the FCC is perfectly capable of distinguishing between legitimate Part 15 operation and jamming.

What the hotel used was not a RF-shitting noise source/jammer of any sort, it was other properly certified/permitted Part 15 legal 802.11 wifi equipment equipped with "rogue access point containment" software features that perform deauth attacks in the 802.11 air protocol. Example:

https://www.google.com/search?client=ubuntu&channel=fs&q=cis...

It is grey. It is illegal to jam, this is not jamming.

it's not illegal to crap up the half duplex medium of Part 15 wifi bands

It certainly can be. "Willful or malicious interference," 47 USC 333. If you're going to split hairs, at least know what the fuck you're talking about.

Emitting noise for the purpose of crapping up the wifi band is still malicious. If 2000 moms bring baby monitors to a conference is one thing, but entirely different than thinking you've found a sneaky legal hack by stuffing 2000 baby monitors into your suitcase.

I want to play... :-)

What is willful? e.g. in the case of 2000 moms at a conference or a hotel/building with excessive wifi/etc. Would some of those fall under "willful interference"? Especially as willful and malicious is combined exclusively ("or") in writing.

When they say 'accept interference' they mostly mean that it won't malfunction and jam other services when it recieves interference.

They aren't making any comments about the legality of the source of the interference.