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Comment by LarryMullins | Hacker News Reader

Short of lining your walls with foil, how could you defeat it legally? Jamming isn't legal.

We need new legislation to ban this, without a law enforcement exemption. I don't have high hopes.

"Jamming" is legal in as much as any device that operates in the ISM[0] bands must accept interference - so in the 2.4GHz example, microwave ovens, baby monitors, TV relays, remote door monitors, wireless alarm systems etc., all operate in the same band and will interfere with WiFi that is close by (since they use a different modulation).

[0] https://en.wikipedia.org/wiki/ISM_radio_band

You are correct that ISM band devices must accept interference, however jamming is illegal in the USA due to FCC regulations: https://www.fcc.gov/general/jammer-enforcement

Definitely start with the presumption it is illegal anywhere in the world, even though you might be able to hack around regulations to find loopholes. I think the FCC is focused on broadcast interference, safety requirements, and commercial sales of jamming devices.

And in college I remember a professor or a TA demonstrated jamming by operating a modified microwave oven while running iperf or something similar on a nearby Wi-Fi network.

I would take a wild guess that it wouldn't be jamming, but some sort of network configuration. Maybe something like extra access points with specific geometry, higher power exterior APs than interior APs, or random beam forming or reflections.

Jamming could still be an option. Most devices are required to accept any interference from other lawful devices. So in theory, you could find legal ways of jamming.

https://www.zdnet.com/article/how-to-jam-your-neighbors-wi-f...

The same law that says you must accept interference also says you may not cause interference, or something like that.

You could only legally jam by making transmissions that are actually useful and just happen to also interfere.

IANAL.

Lining the exterior walls doesn't sound all that hard for a new build. Just lay the RF blocking sheet down before the drywall. People love those RF blocking wallets that have dubious value, a "privacy wall" upgrade from builders would probably sell well.

They can sell it as improving Wi-Fi in your own home too, even if you trust neighbors not to pull any shenanigans, since your Wi-Fi network won't be subject to interference from neighboring networks.

Downside is that your cellphones would also stop working indoors.

That's an inconvenience for guests but you could stick a QR code to join your wifi on the wall. Phone calls should still work over wifi calling I'd think.

Just put a mini cell tower/booster on the inside of your house connected via wire to the outside. Problem solved, and you now have the ability to cut off cell access on the inside if you want to.

Okay so nobody will buy it.

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