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Does anyone know how to tell if a wifi device uses beam-forming versus omnidirectional microwave emissions? I imagine that beam-forming devices expose people to

by Cieplak 10y ago

Does anyone know how to tell if a wifi device uses beam-forming versus omnidirectional microwave emissions? I imagine that beam-forming devices expose people to less microwave radiation (2.4 and 5 GHz). Somewhat alarmist but an interesting perspective: https://m.youtube.com/watch?v=F0NEaPTu9oI https://m.youtube.com/watch?v=F0NEaPTu9oI

striking 10y ago
> Somewhat alarmist https://en.wikipedia.org/wiki/Microwave#Effects_on_health https://en.wikipedia.org/wiki/Microwave#Effects_on_health Microwaves can't hurt you unless you focus the hell out of them, right at yourself. Even then, they can't make you experience the health effects that this handsome fellow was talking about (insomnia, really?). You might get buzzing in your ears if you're right next to a radar dish... and that's about it. FCC guidelines on radio emissions are pretty strict. If people were baking themselves with their Wi-Fi routers, someone would've filed a lawsuit by now. This is what's wrong with TED Talks, and with pop sci / pseudoscience in general. It's all excitement, no truth. See also, "power poses": http://www.chronicle.com/article/When-Big-Ideas-Go-Bad/238544?key=yop9k7-B1QiWD6aZpWTJrwQaFFjhgu-cumdsNS97tdI-aTlXSFvHWZIy2iA1Y0UfSDdsb1ZES1NjYnd5QTllSDNlSG9LVjAzRUl3NVNrVGZhUzRMSWJ5Q1BGdw http://www.chronicle.com/article/When-Big-Ideas-Go-Bad/23854...
- baobrien 10y ago
  The linked talk is also TEDx -- even less vetting than normal TED.
- Cieplak 10y ago
  I agree with your overall point that the talk's claims are overblown. > unless you focus the hell out of them By this you mean, increase the intensity of the radiation? Obviously, a person would die inside a microwave oven that uses the same frequency as wifi (2.4Ghz). But it seems myopic to dismiss the possibility that there are no other dangerous effects besides heating. There is still much ongoing research on the effect of pulsed/modulated microwave radiation (as opposed to continuous radiation). As another example, certain RF harmonics are particularly dangerous: At frequencies near the body's natural resonant frequency, RF energy is absorbed more efficiently, and maximum heating occurs http://www.arrl.org/rf-radiation-and-electromagnetic-field-safety http://www.arrl.org/rf-radiation-and-electromagnetic-field-s...
  - striking 10y ago
    Look at it this way: regardless of how dangerous you believe WiFi to be, there's a much, much greater chance that you'll die in a car accident on your way to work. Or an unrelated heart attack. But I'll take you at your word. Here's how you can calculate flux density caused by your router: http://physics.stackexchange.com/a/48092 http://physics.stackexchange.com/a/48092. Then compare that calculation to the graph shown here for safety information: http://www.arrl.org/files/file/Technology/RFsafetyCommittee/hbkrf.gif http://www.arrl.org/files/file/Technology/RFsafetyCommittee/... Furthermore, the FCC limits router wattage to 1W. The IEEE says that you shouldn't worry about radiation below 7W. That's on the same page you linked above. There are specific limits on this sort of radiation. If anything you've said were true, a lot of people would've gotten sued by now. And myopic or not, true or false, I have more things to think about than WiFi radiation. Link me a peer-reviewed study or else stop fear-mongering.
esaym 10y ago
The periodic beacon has all that info. In this[0] example you'll see the "Transmit Beamforming" field has a hex value of all zeros. Which either means unsupported or it is completely implicit. [0] https://mrncciew.files.wordpress.com/2014/10/cwap-ht-ie-17.png https://mrncciew.files.wordpress.com/2014/10/cwap-ht-ie-17.p...
baobrien 10y ago
That talk is entirely baseless fear mongering. Electromagnetic Hypersensitivity is entirely unsupported by the science.
- alkonaut 10y ago
  Well, to be fair it IS a proper diagnosis and an active area of research even at "good" universities. Of course this research takes place in the department of psychology, not the department of antennas...
Johnny555 10y ago
If you're really worried about the radiation, I'd be more worried about beamforming than no beamforming -- If you use a mobile device, the Wifi beam forming will try to maximize signal to your device, which will expose you to the most radiation.
kefka 10y ago
Microwaves are perfectly safe as long as the data is "0"s. The "1"'s can hurt you.. /snark

by Cieplak 10y ago

striking 10y ago

> Somewhat alarmist https://en.wikipedia.org/wiki/Microwave#Effects_on_health https://en.wikipedia.org/wiki/Microwave#Effects_on_health Microwaves can't hurt you unless you focus the hell out of them, right at yourself. Even then, they can't make you experience the health effects that this handsome fellow was talking about (insomnia, really?). You might get buzzing in your ears if you're right next to a radar dish... and that's about it. FCC guidelines on radio emissions are pretty strict. If people were baking themselves with their Wi-Fi routers, someone would've filed a lawsuit by now. This is what's wrong with TED Talks, and with pop sci / pseudoscience in general. It's all excitement, no truth. See also, "power poses": http://www.chronicle.com/article/When-Big-Ideas-Go-Bad/238544?key=yop9k7-B1QiWD6aZpWTJrwQaFFjhgu-cumdsNS97tdI-aTlXSFvHWZIy2iA1Y0UfSDdsb1ZES1NjYnd5QTllSDNlSG9LVjAzRUl3NVNrVGZhUzRMSWJ5Q1BGdw http://www.chronicle.com/article/When-Big-Ideas-Go-Bad/23854...

baobrien 10y ago
The linked talk is also TEDx -- even less vetting than normal TED.
Cieplak 10y ago
I agree with your overall point that the talk's claims are overblown. > unless you focus the hell out of them By this you mean, increase the intensity of the radiation? Obviously, a person would die inside a microwave oven that uses the same frequency as wifi (2.4Ghz). But it seems myopic to dismiss the possibility that there are no other dangerous effects besides heating. There is still much ongoing research on the effect of pulsed/modulated microwave radiation (as opposed to continuous radiation). As another example, certain RF harmonics are particularly dangerous: At frequencies near the body's natural resonant frequency, RF energy is absorbed more efficiently, and maximum heating occurs http://www.arrl.org/rf-radiation-and-electromagnetic-field-safety http://www.arrl.org/rf-radiation-and-electromagnetic-field-s...
- striking 10y ago
  Look at it this way: regardless of how dangerous you believe WiFi to be, there's a much, much greater chance that you'll die in a car accident on your way to work. Or an unrelated heart attack. But I'll take you at your word. Here's how you can calculate flux density caused by your router: http://physics.stackexchange.com/a/48092 http://physics.stackexchange.com/a/48092. Then compare that calculation to the graph shown here for safety information: http://www.arrl.org/files/file/Technology/RFsafetyCommittee/hbkrf.gif http://www.arrl.org/files/file/Technology/RFsafetyCommittee/... Furthermore, the FCC limits router wattage to 1W. The IEEE says that you shouldn't worry about radiation below 7W. That's on the same page you linked above. There are specific limits on this sort of radiation. If anything you've said were true, a lot of people would've gotten sued by now. And myopic or not, true or false, I have more things to think about than WiFi radiation. Link me a peer-reviewed study or else stop fear-mongering.

esaym 10y ago

The periodic beacon has all that info. In this[0] example you'll see the "Transmit Beamforming" field has a hex value of all zeros. Which either means unsupported or it is completely implicit. [0] https://mrncciew.files.wordpress.com/2014/10/cwap-ht-ie-17.png https://mrncciew.files.wordpress.com/2014/10/cwap-ht-ie-17.p...

baobrien 10y ago

That talk is entirely baseless fear mongering. Electromagnetic Hypersensitivity is entirely unsupported by the science.

alkonaut 10y ago
Well, to be fair it IS a proper diagnosis and an active area of research even at "good" universities. Of course this research takes place in the department of psychology, not the department of antennas...

Johnny555 10y ago

If you're really worried about the radiation, I'd be more worried about beamforming than no beamforming -- If you use a mobile device, the Wifi beam forming will try to maximize signal to your device, which will expose you to the most radiation.

kefka 10y ago

Microwaves are perfectly safe as long as the data is "0"s. The "1"'s can hurt you.. /snark