Better at the Low End, Mixed Feelings Everywhere Else

Brian came up with the plan to enable the numerical signal strength visualization and executed on it very well in our original iPhone 4 review. Since then there’s been a disturbing amount of debate as to whether or not this actually amounts to a problem with the phone.

Part of the confusion stems from the fact that doing this sort of antenna testing in a real world scenario is time intensive. As Brian mentioned on the previous page, for today’s article both of us were driving around our respective cities, stopping at various locations, measuring signal strength and comparing it to bar mappings in order to produce the charts you saw on the other page.

There’s no denying that Apple has played a significant role in why there continues to be debate about the iPhone 4 antenna. By simply addressing the pre-4.0.1 bars not being a good representation of signal strength and ignoring the fact that the iPhone 4 does lose more signal strength than competing phones depending on how you hold it, Apple manages to convince its faithful that there’s nothing wrong while driving its critics to demand a recall.

My mother always taught me that honesty is the best policy and presumably I’m not the only one in the world who was privy to this information. Had Apple come clean with both of these facts (the bar mapping and the signal attenuation issue) early on we’d be in a far more clear cut world today.

We have consistently argued that the 4’s antenna is a design choice by Apple. As we’ve seen in our testing there are situations where the iPhone 4’s antenna makes things better (e.g. holding onto calls with very low signal strength) and other situations where the design makes them worse (e.g. holding it wrong in situations with low signal strength). I wanted to describe the inconsistency in greater detail so I went out with an iPhone 3GS and 4 and documented my experiences.

In practice I found three things that were true about the iPhone 4’s antenna behavior compared to the 3GS.

Reception in average conditions is sometimes significantly better on the iPhone 4 than on the 3GS. Take a look at the image capture below. In the same exact location we have better reception on the 4 than the 3GS. Granted this could be due to a number of variables outside of the phone’s antenna itself, but it happened enough times that it’s worth reporting. This is the positive to Apple’s external antenna design - you can and do get better reception. Unfortunately the tradeoff is the scenario I just described before this.

iPhone 4 (left) at -81 dBm vs. iPhone 3GS (right) at -94 dBm

Signal strength is sometimes the same as or worse than the iPhone 3GS. This is really where the problem comes into play. In the shot below I have the 4 and 3GS sitting next to one another and they are displaying roughly the same signal strength. We’ve already proven that holding the iPhone 4 attenuates its signal more than the 3GS, which results in the frustration we’ve seen expressed by many at this point. In situations where the 4 has the same signal as the 3GS, holding the phone is going to drop it to levels significantly worse than the 3GS. If you’re in an area with low signal strength to begin with, holding the phone is going to bring you down to dangerously low levels.

iPhone 4 (left) at -103 dBm vs. iPhone 3GS (right) at -104 dBm

iPhone 4 being held tightly (left) at -115 dBm vs. iPhone 3GS being held tightly (right) at -107 dBm

iPhone 4 (left) at -77 dBm vs. iPhone 3GS (right) at -66 dBm

The iPhone 4 is better at holding onto calls and data at very low signal levels. We’ve mentioned this one before but it’s worth reiterating. The new antenna does let me make calls and transmit data at very low signal strength. With the iOS 4.0.1 update I was able to make a call at -115dB on the 3GS, however the call did drop within a minute of starting it. By comparison I was able to have a much longer conversation without dropping the call at -120dB on the 4. By no means is this a scientific comparison, but anecdotally both Brian and I feel that the low signal strength performance of the iPhone 4 is better than the 3GS.

A call at -120 dBm on the iPhone 4

If you’re keeping tabs you’ll note that this is what is traditionally referred to as a trade off. Apple opted for good performance in low signal situations (and style of course) over maintaining consistently better or unchanged radio performance compared to the 3GS. I would personally consider this to be an unnecessarily risky design choice, particularly for a smartphone vendor. Note that it's nearly impossible to separate out the antenna from the rest of the iPhone 4 platform to determine exactly what is responsible for the phone's signal sensitivity in various situations. All we ultimately know is how physically interacting with the antenna impacts reported signal strength.

I can’t stress enough that this issue impacts all users. The variability is in how strong of a signal you have to begin with. That’s the absolute only reason there’s debate in these discussions from phone to phone. At my desk I don’t get great reception on AT&T. With the iPhone 4 I’m usually at -96dBm. If I keep a tight grip on the phone or if I’m holding it to send text messages I can sometimes lose all signal entirely. This is a combination of poor reception at my house and the fact that the 4 loses more of its signal than other phones when held certain ways.

Brian on the other hand has much better reception at his home. To him, the signal strength drops but it does not drop enough for this to be a problem. I consider myself to be on the border. If I’m mindful of how I’m holding the phone it’s not an issue, and even most of the time if I’m not paying attention to it it’s not an issue. However there are definitely times when it does become a problem. I wouldn’t consider it to be the majority of the time or even more than 10% of the time, but it happens enough for me to have to think about it. Ultimately this is why I consider Apple’s design here to be unnecessarily risky. Introducing a change with stylistic and technical benefits where the downside is limited but potentially very noticeable is just ballsy.

Luckily for Apple, there are things that can be done about it.

The Bars Have Changed Mitigating the Problem with Tape/Gloves


View All Comments

  • mac11 - Friday, July 16, 2010 - link

    Glad I had the patience to read thru this long article. It's logical, unbiased, THOROUGH, and grammatical(meakes it more pleasant to read). After reading 1,000 article titles, and over 100 articles referring to the Apple antenna issue / non-issue, I finally come to a rather complete understanding of the matter. I feel at ease now knowing what needs to be known.

    My conclusion: iPhone 4 antenna has greater extended sensitivities, but more susceptible to interference from hand grips than 3GS or Nexus One. And the call can be dropped due to this deeper interference if your starting signal was weak enough to start with. And the re-formulated signal strength bars gives much more truthful representation of your area signal strength.

    Thank you AnadTech.. kudos, and my respecta to your great journalism.
  • a different user name - Friday, July 16, 2010 - link

    How are they showing signal power dB dBm instead of bars on iPhone 4? Reply
  • jmlev - Friday, July 16, 2010 - link

    How do I switch from bars to a -db reading on my iPhone4, like you show in the pictures? Reply
  • gypsy1962 - Friday, July 16, 2010 - link

    Guys, as usual, 1st class commentary! I highly applaud your technical and analytical skills, a skill-set sorely missing in much of the commentary flowing around the net these days... Reply
  • marraco - Friday, July 16, 2010 - link

    The olders bars jus were a hoax to cheat buyers into thinkin than the device got better signal than competing products.
    Again the same history. Marketing propaganda.
    Now also Apply blames the buyer over a design flaw, pretending that the signal is lost because the owner grab the device in wrong way.

    This is from a company that pretends to charge high prices for “better” quality.
  • betanerd - Friday, July 16, 2010 - link

    When you referred to the "signal reporting lie that started with the 3g". Are you referring to When it was released people complained about poor signal. Then Apple released an "update" that supposedly fixed it. I remember something of the sort happening. Perhaps the pr/updates have all be to make owners feel better till the next itteration. 3g complaint: bad signal-->update disproportionate(signal readout inflation) bar formula. ip4 complaint: signal drops/bad signal -->update more proportionate bar formula(your signal isn't really that good) + bigger, easy to read, confidence(ala enzyte) inspiring bars. Has/can anyone checked older releases to see if this is the case. If so it may make the argument/lawsuit stronger. Not that I wish any ill will towards Apple.

    +Some have mentioned a possible problem with they way the micro sims are cut. Where the contacts touch the metal sim tray which touches the metal antenna band. Any truth to that?

    +Perhaps placebo effect Have any reports come in about different serial numbers? Such as 8___=death grip susceptible, 7____=not susceptible? from Mac rumors it may have been debunked but, i was from a sample of 1.

    + Have any owners that say they have no problems come forward to have their phones tested or recored the testing by death grip and multimeter?

    I'm not sure how much it matters...Free cases till Sept30!
  • Hxx - Friday, July 16, 2010 - link

    apple announced that they will give a free protective case
  • v12v12 - Friday, July 16, 2010 - link

    I love it... watching the illogical, the brainwashed and zombified consumer-cattle actually try and defend a company (irregardless of if it's "Apple" or not) that's been factually proven over many, many years to actively and purposefully defraud consumers with falsified and heavily padded performance (G4/5 anyone?) data. Documented and legally proven accounts of advertising and marketing fraud (search it yourself if you're gullible enough to ask) to further profits. Settling many justified lawsuits out of court (Creative for 100MIL?!) as to not have to admit “wrong doing,” or face the laws they’ve broken…
    __This company is well known (factually documented) for using strong-arm tactics to control vendors AND even their own consumer base... Yes "Apple" tells you it's YOU that has the problem, even if it's them. Blah blah, this isn't a bash, for these shady practices apply to many other competing companies as well.

    So here's your insanity; you the consumer-cattle (pleb) are required by law to pay in full, up front for this device. They are required to render to you a FULLY WORKING device for which you paid. You find out that the device is bugged/not working 100% AS ADVERTISED (there's a law for that also) and now you're looking for retribution, but are told "sorry, there's no problem." It's YOUR problem I guess? Mean while what's going on behind the scenes are nothing but meetings on how to keep the "problem" internalized, until they can find a 'solution'..." in the meantime you are left with little recourse to solving this issue until Apple tells you??? Ever tried to return an iPhone, you'd think you were trying to return a bomb from the vehement response from the "geniuses" at the Apple store... So what now, yep just sit there and WAIT for Apple to tell you what or if there's a problem (regardless if Anand/Gadget/someone else proves it) at all... Then more waiting on a "solution," but all the while WHO is reimbursing you for your time, hassle, lack of service, AND interest on your money they now have possession of...

    Why is it that as the consumer, you/we have to go through all these hoops, lies, tricks and turmoil over a device that's been PAID FOR IN FULL? Turn the logic around and apply the same habitual shenanigans to consumer behavior, and Apple will send you a court summons to get "their" money asap! Heck they might refuse service to you based on your shoddy track-record. "Oh you say my check/CC didn't clear... sorry it's cleared, there's something wrong with your machines kthxbye..." "What, you want me to send you extra money b/c the 1st installment didn't fully cash out? Sorry I'll get you the money when I get it..." "Oh you want the money right now, and extra for your troubles... yeah umm, I'll let ya know when I get the rest (I still say it's your machines in error), but for now, here's $5 to tide you over..."

    Would this bull-shat work if the tables were turned, hell fscking NO it wouldn't work... so who in their right mind expects to get what they've been told they'll get? This crap is just laughable... year after year, product "upgrade" after upgrade; you are still getting hustled by Apple/Vzn/big-business and there's naves out there so fanatical and brainwashed into defending these overt, mega greed based institutions. Lol INSANITY… But there’s relief in knowing no matter how factual, logical, common-sense based your diatribe is, SOME cattle just won’t ever get it. They’ll keep buying, supporting these businesses that want nothing but to rip you off and leave you with whatever you get; “working” or not… Slave mentality to the MAX… lmfao (Though I do wish Anand/Tom etc would stop with the hand slapping and stick these criminals in the FIRE they deserve.)
  • SunSamurai - Friday, July 16, 2010 - link


    Show us on the doll where apple touched you.
  • Levictus - Saturday, July 17, 2010 - link

    Do you get paid to defend Apple from criticism or something? Because you seem a little too obsessed with arguing with people who criticize Apple. I mean if you like their products or are into Steve Jobs, good for you. You need to understand that there are people who have other interests in life than Apple's products and marketing. Reply

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