All Things Tarun

  • 09:11:55 pm on July 22, 2010 | 0
    Tags: , , , , , , , , ,

    John Gruber yesterday posted a response to an argument regarding the iPhone 4 testing design:

    We know from the Gizmodo stolen iPhone that the prototypes were disguised in cases when outside Apple’s campus. Maybe that’s why Apple missed this flaw in the antenna: they never noticed it on campus because they have a strong AT&T signal, and never noticed it off campus because the iPhones were always inside cases, and cases mitigate the skin-touching-the-spot problem.

    First point:

    For one thing, the strength of the AT&T coverage on Apple’s campus has no bearing on the testing they perform in their lab. There is no signal from AT&T inside those anechoic chambers. There is no signal from any external wireless source in those chambers. That’s the point of them. The way the chambers work is that they create their own little mini network inside the chamber. They run tests where they create strong signals, weak signals, and everything in between. They also run tests with people holding the phones being tested.

    They run tests where the signals are created by them, either strong or weak, but that is different than a test where hundreds of thousands of people are using that same “test” network at the same time. However, if the Anechoic chambers can simulate that kind of overload (which, at $100 million, they better), then I can see how Apple had some solid tests within the campus. I wonder if perhaps Apple had multiple cellphones within the chamber at once and would test them all at the same time to simulate an actual network overload.

    For another, they do test antennas in the field off-campus with no case. They do so using a fleet of about a dozen mobile testing labs. These are vans — more like small buses, maybe — which contain a slew of testing and measurement equipment.

    Definitely true, but once you leave campus there is obvious interference, unless the mobile lab is also sealed as a perfect Faraday Cage. I guess we can trust Gruber as he is well-connected with these matters.

    The iPhone Gizmodo obtained was, in Apple’s internal lingo, a Design Verification Test (DVT) unit. These are one step below production units. My understanding is that when DVT units are deemed ready to go, the factories start churning them out as actual production units. Those DVT field tests are the final tests, certainly not the only tests. During the tour of Apple’s labs, Ruben Caballero — Apple’s senior antenna engineer, who led the tour — said the iPhone 4 antenna design had been in testing for two years.

    So as a DVT then, Apple has committed to the antenna design, even with all of the other antenna tests showing a potential flaw? Steve remarks that he did not know the issue would be so large, and you have to wonder which models of the iPhone 4 he actually got to play with himself, or what reports he received while the iPhone was in production, rather than at the DVT stage. If Steve was just told later on that “by the way, there is a weak spot here” but it “isn’t a big deal”, of course that essentially sweeps the issue under the rug and makes it something that could be missed.

    In all, I don’t think it is “not possible” for Apple wasn’t aware of the signal issue due to the antenna testing procedure. Yes, Apple did invest an unholy amount of money on facilities, vans and the like, but given the small spot, the small number of people actually allowed to test it, it is reasonable to say that this was a greatly overlooked (not missed) issue.


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