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A lot of these smartphones go through imperical tests in an anechoic chamber managed by a third party lab to see if they’re bellow the allowed levels in each ba

by swiley 7y ago

A lot of these smartphones go through imperical tests in an anechoic chamber managed by a third party lab to see if they’re bellow the allowed levels in each band. That sounds hackish but (IMO) isn’t the end of the world. What weirds me out is that they’ll send them to these third party labs and repeatedly test some small number (possibly one) of devices until it’s right up against what’s allowed. That feels less than scientific and probably wrong although I’m not sure what I’d change.

xondono 7y ago
The main problem with all this kind of testing is how little precision there is. “Double the energy limit” sounds a lot, but for a lot of these labs that’s inside of the error range of their equipment.
TaylorAlexander 7y ago
I’m sure Apple has their own test chambers.
deftnerd 7y ago
The "conspiracy" portion of my brain makes me wonder if it's possible that Apple phones have lower power levels if the location services determines that the phone is in a location with a known anechoic chamber. There can't be that many of them. Such behavior has already been shown by automobile manufacturers during the "diesel-gate" incidents.
- swiley 7y ago
  You don’t have to do that, usually you’ll run special test firmware on the device and say that this behaves appropriately (I’ve done this for other companies) Remember that this is fundamentally a legal/social thing that involves engineering/science and not the other way around.
  - jjoonathan 7y ago
    Right, you're supposed to test to the worst case and you get to define "worst case." Cheating would be as simple as defining a favorable "worst case." Before the tin-foil crowd calls regulators stupid, I'd like to point out that in the absence of cheating this allows hardware engineers to do a better job & design a system that is robust to software shenanigans. That's a nice thing. Maybe we cannot have nice things, but if so, let's prove it rather than presuppose it. I'd estimate the likelihood of cheating by looking to see if people are choosing phones on the basis of EIRP the way they choose cars based on MPG. I don't see that happening, so I estimate that the likelihood of cheating is low, and would vote to keep the cooperative model around.

by swiley 7y ago

xondono 7y ago

The main problem with all this kind of testing is how little precision there is. “Double the energy limit” sounds a lot, but for a lot of these labs that’s inside of the error range of their equipment.

TaylorAlexander 7y ago

I’m sure Apple has their own test chambers.

deftnerd 7y ago

The "conspiracy" portion of my brain makes me wonder if it's possible that Apple phones have lower power levels if the location services determines that the phone is in a location with a known anechoic chamber. There can't be that many of them. Such behavior has already been shown by automobile manufacturers during the "diesel-gate" incidents.

swiley 7y ago
You don’t have to do that, usually you’ll run special test firmware on the device and say that this behaves appropriately (I’ve done this for other companies) Remember that this is fundamentally a legal/social thing that involves engineering/science and not the other way around.
- jjoonathan 7y ago
  Right, you're supposed to test to the worst case and you get to define "worst case." Cheating would be as simple as defining a favorable "worst case." Before the tin-foil crowd calls regulators stupid, I'd like to point out that in the absence of cheating this allows hardware engineers to do a better job & design a system that is robust to software shenanigans. That's a nice thing. Maybe we cannot have nice things, but if so, let's prove it rather than presuppose it. I'd estimate the likelihood of cheating by looking to see if people are choosing phones on the basis of EIRP the way they choose cars based on MPG. I don't see that happening, so I estimate that the likelihood of cheating is low, and would vote to keep the cooperative model around.