In the US, is it legal to jam radio/cell communications if such jamming is entirely confined to your own private property? And does it matter whether you are in a building or not?

Imagine now that you have constructed a Faraday cage on your property so that external radio/cell signals cannot enter and internal radio/cell signals cannot exit. If you are inside the Faraday cage, is it legal or illegal to operate a radio/cell jammer?

These questions are intended to ask about the legality of a private citizen doing this without knowledge or approval by any governmental authority. If the jurisdiction typically matters let's say New York, New York, USA.

  • I would be redundant to jam radio within a Faraday cage unless you are trying to keep to devices within the cage from talking.
    – Sam
    Sep 29 '16 at 13:55

Yes, if it works. FCC regulations allow operation of interfering equipment (for tests and experiment) provided the interference is fully contained in a Faraday cage. You must still "comply with the general prohibition against causing harmful interference to other spectrum users".

  • I see, so you're suggesting that the FCC announcement in the Federal Register wasn't "official"? Well, CFR is such horrendous spaghetti, but I will see if I can come up with a number.
    – user6726
    Nov 5 '16 at 0:08
  • I managed to find it 47 CFR Section 5.54f. Also, I don't believe pointing to the Federal Register as justification for your actions would hold up in court, so, yes, I wouldn't accept the Federal Register alone. Especially since the applicable codes could have been later modified (Your link was from 2013)
    – Matt
    Nov 5 '16 at 0:12

No. It is a criminal offense, punishable by up to 1 year in jail or up to a $10,000 fine (plus forfeitures) for a first offense, and up to two years in prison or up to a $10,000 fine (plus forfeitures) for a second or subsequent offense.

  • "radio communications of any station licensed" note the words "station licensed".
    – Sam
    Sep 28 '16 at 15:13
  • @Sam "...or authorized..." Unlicensed Part 15 operation is included.
    – cpast
    Sep 28 '16 at 21:54
  • 1
    The interesting question is whether it counts as "interference to radio communications" if you only jam inside your own home, where no one but you is inconvenienced. But probably yes.
    – sleske
    Sep 29 '16 at 7:42
  • 1
    @sleske And what about inside the cage? We assume no radio/cell signals enter from the outside, so jamming on the interior would not interfere with licensed or authorized stations' signals. The Faraday cage / anechoic chamber "interferes", however; are they illegal? For that matter - so does even the most inert electrical insulator insofar as it is a better conductor of electrons than empty space. Does my using a metal spoon, willfully and knowing it disrupts licensed signals, violate this law?
    – Patrick87
    Sep 30 '16 at 3:00
  • @Patrick87 Probably not. The section is in a part of the Communications Act that generally is about transmission, and the history of it is that it was an FCC regulation that Congress decided, at the request of the FCC, to elevate to a statutory provision (it gives it more teeth and a higher profile than a regulatory violation). Also, "jamming on the interior would not interfere with licensed or authorized stations' signals" -- not necessarily. Authorized or licensed stations can be inside and communicating with other stations inside.
    – cpast
    Sep 30 '16 at 3:59

I am not a lawyer, but probably. Many companies (antenna makers, test equipment makers, etc) effectively do exactly that in https://en.wikipedia.org/wiki/Anechoic_chamber. As long as your anechoic chamber has no leakage, you can probably do anything you want in it from an RF perspective.

  • Congress has made it a crime, without regard to public vs. private property or anechoic chambers.
    – cpast
    Sep 28 '16 at 21:57
  • @cpast, can you cite any case law? The law you cited provides no exceptions for Anechoic chambers, and I was in one used for government approved research not 15 minutes ago that would literally fry your cell phone. So you are unequivocally wrong.
    – Sam
    Sep 29 '16 at 13:54
  • Was it doing that to jam your communications, or to do research that had the incidental effect of that? Because the law is "willful or malicious," not "incidental." The question didn't say "operating high-power RF stuff that incidentally would jam communications," it said "operating a jammer."
    – cpast
    Sep 29 '16 at 13:56
  • 1
    I point out in a comment in the other answer that inside the cage/chamber there are no licensed signals with which to interfere (or we can presume as much since we control what goes inside). In that sense, perhaps the jamming is OK. But what about the cage/chamber itself? What about anything that interferes with radio/cell signals - that is, any matter whatsoever? The law makes no mention of the degree of interference which is prohibited.
    – Patrick87
    Sep 30 '16 at 3:05
  • 1
    @Patrick87 Better not stand in front of someone's cellphone!
    – user253751
    Nov 9 '16 at 8:20

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.