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I've thought about controlling mobile data for specific high-security scenarios. My design, which I never got to try out, was to cover the walls in RF shield p

I've thought about controlling mobile data for specific high-security scenarios. My design, which I never got to try out, was to cover the walls in RF shield paint, there is a corresponding film for windows. Then you can install an indoor LTE antenna/booster on a physical switch and viola, managed access to data. Jammers like this in the US (and apparently from this article, other jurisdictions) are illegal if their effect reaches beyond your property since it can block access to emergency services, etc. I think RF containment is a legally-safer strategy.

pdabbadabba 5y ago
> Jammers like this in the US (and apparently from this article, other jurisdictions) are illegal if their effect reaches beyond your property since it can block access to emergency services, etc. I think RF containment is a legally-safer strategy. Without commenting on the legality of your RF containment idea, it's worth noting that jamming is also illegal in the U.S. even if confined to your own property. The Communications Act, 47 U,S,C, 333, prohibits causing "willful or malicious interference" to a radio licensee categorically, regardless of where it occurs. That is why the FCC fined Marriott Hotels $600,000 for operating a jammer[1] at their own resort property. https://docs.fcc.gov/public/attachments/DA-14-1444A1.pdf https://docs.fcc.gov/public/attachments/DA-14-1444A1.pdf [1] The FCC treated it as a jammer, so the example applies for illustrating the scope of 333. But it's worth noting out of interest that, in this case, Marriot was transmitting Wi-Fi deauthentication packets to keep people off of private AP--presumably in an attempt to force conference attendees to pay for the resort's Wi-Fi service. Regardless, the FCC concluded that this constituted willful interference. Edit: It would be more accurate to have said that the FCC treated Marriott's behavior in that case as causing "willful interference." The actual feature of the equipment that they used (which I think was a standard enterprise Wi-Fi AP) has other legitimate uses. She FCC did not say that the equipment itself was a jammer across the board.
- fennecfoxen 5y ago
  [1] n.b. the purpose of that feature is to deauthenticate your own organization's computers if they try to connect to an access point that is not operated by your organization (e.g. if someone accidentally connects to the phishers operating m4riott-c0rp).
- thfuran 5y ago
  >Marriot was transmitting Wi-Fi deauthentication packets to keep people off of private AP- Isn't that a standard feature on most enterprise access points? It is in Ruckus's at any rate.
  - pdabbadabba 5y ago
    Yes. Though I believe some vendors caution users about using the feature in the U.S. There are probably permissible uses for it, such as bona fide network maintenance and security. So I don't believe that the feature itself is illegal--Marriott just used it in an illegal way.
josephcsible 5y ago
IMO, buildings that are effectively Faraday cages to cell frequencies should be considered unsafe for human occupancy unless they have emergency phones every 8 feet along every wall, and an automatic backup generator unless all of the phones have copper wires all the way to the phone company.
- Jon_Lowtek 5y ago
  phones used by humans are far too unreliable for the level of safety you require. What you need are mandatory wireless health monitoring implants and the required installation of transmitters in any building shielded against their frequencies. For optimum safety add a shocker so any unsafe behavior can immediately be reprimanded by the authorities. </snark>
  - josephcsible 5y ago
    I don't want any new monitoring or emergency equipment to be mandatory. But if someone chooses to have such equipment, building owners shouldn't be allowed to just forcibly disable it.
istjohn 5y ago
I think you'd find it much harder to block RF signals than you would expect. As Matt Blaze found[1], creating even a small effective faraday cage can be quite difficult, and I imagine the problems only compound as you scale up. 1. https://www.mattblaze.org/blog/faraday/ https://www.mattblaze.org/blog/faraday/

pdabbadabba 5y ago

> Jammers like this in the US (and apparently from this article, other jurisdictions) are illegal if their effect reaches beyond your property since it can block access to emergency services, etc. I think RF containment is a legally-safer strategy. Without commenting on the legality of your RF containment idea, it's worth noting that jamming is also illegal in the U.S. even if confined to your own property. The Communications Act, 47 U,S,C, 333, prohibits causing "willful or malicious interference" to a radio licensee categorically, regardless of where it occurs. That is why the FCC fined Marriott Hotels $600,000 for operating a jammer[1] at their own resort property. https://docs.fcc.gov/public/attachments/DA-14-1444A1.pdf https://docs.fcc.gov/public/attachments/DA-14-1444A1.pdf [1] The FCC treated it as a jammer, so the example applies for illustrating the scope of 333. But it's worth noting out of interest that, in this case, Marriot was transmitting Wi-Fi deauthentication packets to keep people off of private AP--presumably in an attempt to force conference attendees to pay for the resort's Wi-Fi service. Regardless, the FCC concluded that this constituted willful interference. Edit: It would be more accurate to have said that the FCC treated Marriott's behavior in that case as causing "willful interference." The actual feature of the equipment that they used (which I think was a standard enterprise Wi-Fi AP) has other legitimate uses. She FCC did not say that the equipment itself was a jammer across the board.

fennecfoxen 5y ago
[1] n.b. the purpose of that feature is to deauthenticate your own organization's computers if they try to connect to an access point that is not operated by your organization (e.g. if someone accidentally connects to the phishers operating m4riott-c0rp).
thfuran 5y ago
>Marriot was transmitting Wi-Fi deauthentication packets to keep people off of private AP- Isn't that a standard feature on most enterprise access points? It is in Ruckus's at any rate.
- pdabbadabba 5y ago
  Yes. Though I believe some vendors caution users about using the feature in the U.S. There are probably permissible uses for it, such as bona fide network maintenance and security. So I don't believe that the feature itself is illegal--Marriott just used it in an illegal way.

josephcsible 5y ago

IMO, buildings that are effectively Faraday cages to cell frequencies should be considered unsafe for human occupancy unless they have emergency phones every 8 feet along every wall, and an automatic backup generator unless all of the phones have copper wires all the way to the phone company.

Jon_Lowtek 5y ago
phones used by humans are far too unreliable for the level of safety you require. What you need are mandatory wireless health monitoring implants and the required installation of transmitters in any building shielded against their frequencies. For optimum safety add a shocker so any unsafe behavior can immediately be reprimanded by the authorities. </snark>
- josephcsible 5y ago
  I don't want any new monitoring or emergency equipment to be mandatory. But if someone chooses to have such equipment, building owners shouldn't be allowed to just forcibly disable it.

istjohn 5y ago

I think you'd find it much harder to block RF signals than you would expect. As Matt Blaze found[1], creating even a small effective faraday cage can be quite difficult, and I imagine the problems only compound as you scale up. 1. https://www.mattblaze.org/blog/faraday/ https://www.mattblaze.org/blog/faraday/