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Comment by naz | Hacker News Reader

Does this mean LG is violating the FCC requirement that a device must accept interference?

No, but it raises the question of whether the lack of shielding causing this issue also causes the monitor to radiate excessive RF noise that may interfere with other devices. If it's sensitive to 2.4Ghz signals, there may be signals generated inside it in the same frequency band which can likely escape just as easily as the signal from a router can intrude.

USB 3.0 has been known to interfere with WiFi for quite a while. I think Intel mentioned it when they announced USB 3.

Of course, this is a slightly different signalling mechanism (Thunderbolt 3), but basically, you have to put the spurious emissions somewhere that doesn't interfere with licensed radio services, which basically means 900MHz, 2.4GHz or 5GHz, and they picked 2.4GHz.

http://www.intel.com/content/www/us/en/io/universal-serial-b...

Sounds like it's going above and beyond the regulations by not just accepting the interference, but it's inviting it with open arms.

It's the reverse. The FCC is about jamming the signal not being jammed.

Elaborating, my understanding is that the 'accept interference' bit is more about placing such devices low on the legal totem pole: The TV owner or manufacturer doesn't have a legal right to _not_ be interfered with; it _must accept_ interference. Whether it continues to work or fails after 'accepting' the interference is its own business. With that interpretation, they would be in violation of that clause if they sued the router manufacturer over this.

It's both:

Title 47 - Telecommunication. § 15.5 (b) [...] subject to the conditions that no harmful interference is caused and that interference must be accepted [...]

https://www.gpo.gov/fdsys/pkg/CFR-2015-title47-vol1/xml/CFR-...

Not true.

When the FCC says you must accept interference, that means you have to live with it if the interfering device meets emissions standards. It doesn't mean the device has to be functional in the face of interference.

Are you sure? Seems to be pointless if it just means that it will not be irrecovably damaged.

It doesn't even mean it won't be irrecoverably damaged, it just means the manufacturer of the damaged hardware can't sue the manufacturer of the interfering hardware.

They must accept the interference in a philosophical manner more than a technical one.

Let me try an example: I have an amateur radio rig that transmits only on the allowed frequencies and it meets FCC standards. You are my neighbor using an antenna to get your TV. You allege that my radio transmissions interfere with your TV viewing. Legally, I'm allowed to tell you to pound sand and you have no recourse. Because your TV has to accept radio interference that is otherwise legal, whether your reception is affected or not.

(Of course, because I'm not a complete dick, I would assist my neighbor in properly shielding his TV or otherwise mitigating the situation, rather than tell her to pound sand.

The clause about accepting interference means that the device must not fail when recieving interference in a way that would cause it to radiate on another frequency. Product functional failure otherwise is not regulated in the US. The FCC doesn't care if your product bricks itself as long as it doesn't jam the spectrum.

I've been through this testing before. They blast your device with many different frequecies and measure what comes out.

The test was harder to pass in the old days when there many discrete mixers inside radios and poor isolation between the RX and TX paths through the duplexer.

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