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phoenixdave
WSOCT -- Thanks for posting the analysis. Very well done....
Tunrayo
Now, here is Apple contradicting itself; if the iPhone 4 problem is due to a ...
Apple says iPhone 4 problem is a math glitch
Rick Merritt
7/2/2010 5:54 PM EDT
SAN JOSE, Calif. -- Perceived problems with cellular reception on the Apple iPhone 4 are not due to a poor antenna design, but a faulty formula for reporting reception levels to users, according to a statement issued by Apple Inc.
"Some users have reported that iPhone 4 can drop four or five bars when tightly held in a way which covers the black strip in the lower left corner of the metal band," Apple admitted in its statement released Friday (July 2).
However, the company has "gone back to our labs and retested everything, and the results are the same--the iPhone 4's wireless performance is the best we have ever shipped," the statement said.
The problem, according to Apple, is that "the formula we use to calculate how many bars of signal strength to display is totally wrong. Our formula, in many instances, mistakenly displays two more bars than it should for a given signal strength," the statement said.
Thus when users saw signals drop four or five bars, they were likely already in an area of weak coverage, the company claimed. "Their big drop in bars is because their high bars were never real in the first place," the statement said.
The rationale does not seem to address the problem reported in some cases that users had a usable signal but lost it when they covered the black strip in the lower left corner of the metal band.
An analyst at UBM TechInsights said the iPhone 4 for the first time placed its cellular and GPS antennas in the case's frame. The black strip marked the space between the two antennas that, when bridged by a user holding his hand over it, changed the length and thus the performance of the antenna.
The Apple statement made no comment on the design of the antenna except to say "some have accused the iPhone 4 of having a faulty antenna design."
"Absent sophisticated testing, it is hard to state with certainty whether Apple's claim that it's just a software problem is true or not," said David Carey, a senior UBM TechInsights analyst and founder of the Portelligent teardown service.
"The iPhone 4 antenna design is unique in that the basic internal antenna technology of today's cellphones is now exposed directly to the outside and to direct contact with the hand," Carey said. "Apple's design means it becomes possible for hand effects and degraded RF performance to be more pronounced [than with other handsets] it seems to me," he added.
Separately, the Anandtech Web site said the iPhone 4 in some ways has better cellular reception than competing phones it tested. However, it also said the iPhone 4 is subject to greater signal loss than other phones depending on how the handset is held.
"Apple should add an insulative coating to the stainless steel [antenna] band, or subsidize bumper cases. It's that simple," the Anandtech reviewer said.
Apple said it will address the situation by "adopting AT&T's recently recommended formula for calculating how many bars to display for a given signal strength. We are also making bars 1, 2 and 3 a bit taller so they will be easier to see," the statement said.
"We will issue a free software update within a few weeks that incorporates the corrected formula. Since this mistake has been present since the original iPhone, this software update will also be available for the iPhone 3GS and iPhone 3G," the statement added.
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rick.merritt
7/2/2010 6:25 PM EDT
I'd love to hear some user experiences with the iPhone 4 and opinions of what Apple should do
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prabhakar_deosthali
7/5/2010 3:39 AM EDT
It may be worthwhile for Apple not to cover up the problem but go to the root cause. If the users are experiencing the poor signal reception then it may not be just the wrong display problem.
Prabhakar Deosthali
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elctrnx_lyf
7/5/2010 7:43 AM EDT
When it comes to the mobile signal reception, the RSSI (which indicates the received signal strength) levels seems to be reduced by almost 20dB when the phone is held tight in the hand. As i was following this discussion i spoke to my bro who bought a new iphone4 in Lousiana and he explained that if he holds mobile in the left hand there seems to more signal drop. May be because more palm area at the right side of the phone which consists the EDGE/UMTS antenna.
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GREAT-Terry
7/5/2010 1:13 PM EDT
Technically I don't like the idea of using the metal chassis as antenna. Hold such phone make yourself part of the antenna. If I were you who really love to buy the iPhone4, I would have bought the rubber bumper case.
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phoenixdave
7/5/2010 3:55 PM EDT
From the user commentary I've read, iPhone 4 users seem to be correlating signal strength loss to a drop in the on-screen bar count, and not to a drop of in-progress calls. The Apple update should take care of the first problem, but obviously will have no effect on the second problem. If the actual signal strength is a problem and not the display, the iPhone 4 image will definitely be tarnished. But will it actually negatively affect sales in a big way? Only time will tell, since the Apple devotees are a very committed group. I do think that with the new Droid-run smartphones and open-source Apps, Apple has some serious competition for their target audience, and mis-steps of any kind could prove very costly for them in the long run.
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Xiphos
7/5/2010 4:41 PM EDT
As an all things Apple kind of guy I was disappointed when I got my iPhone4 and could not place or receive calls while at home. My location has always been problematic, but this not even a chance to talk. I don't know what changed, but starting 4 July I received call load and clear with no drops. Overall I'm pleased with the phone and it will take some doing for serious competition to move the Apple audience. It just works.
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Neo1
7/6/2010 2:36 AM EDT
This appears to be the first instance in a long time that Apple overlooked a certain design aspect unintentionally!
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yalanand
7/6/2010 2:57 AM EDT
Interesting comment Xiphos,
Any idea wat changed on 4th July ? Did you change you mobile holding pattern or was that service providers fault. Seems like Apple trying to push problem under the cover by giving some other reasons.
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elctrnx_lyf
7/6/2010 7:49 AM EDT
Coming back to the actual technical issues mentioned about the iphone4 reception quality I'm wondering does using the metal chassis as the antenna is advantages over other methods. What is done in iphone3G? Apple claims the signal strength drop shown is just a math glitch then why no one complained with iphon3G? Apple should dig more into the issue and provide a valuable feedback to the customers.
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DrQuine
7/7/2010 9:09 PM EDT
"Curiosity killed the cat, satisfaction brought it back".
The stories about antenna issues for left handed users and the signal bar display algorithm error have been making the rounds in the popular press as well as more technical circles, such as EE Times. While there has been lots of discussion of the basis for the left handed antenna problem, I've seen no explanation of what the math glitch is that causes the signal strength calculations to be wrong. Engineers are curious people... Any insights?
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ylshih
7/8/2010 2:56 PM EDT
Regardless of whether the signal drop should have been reported as a drop of 2 bars, instead of a drop of 4-5 bars, it's clear that the design is more sensitive to user coupling into the antenna system than other phones. It could still be true that the degraded received signal strength is still better than old designs; that would require testing to prove.
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UIeye
7/9/2010 1:21 PM EDT
I would recommend that AT&T offer free service for new IPhone customers for a few months while they are fixing the problem.
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p51
7/12/2010 5:11 AM EDT
Well we shall see if the software update does indeed prevent signal degradation when held in the same way. Though my feeling is, as others have already pointed out, won't improve things.
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elctrnx_lyf
7/12/2010 12:27 PM EDT
Except Apple, all of us seems to have the same feeling :P
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chanj
7/12/2010 2:06 PM EDT
The idea of embedded the antenna to the chassis is quite a brilliant idea; yet, whether it is engineering possible is still a question. I believe the situation will get better if Apple can stay quiet and focus on looking for a solution in addition to finding the root cause . Regardless of the current situation, iPhone 4 is still selling dozens. Bumper is going along with it (with a cost).
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selinz
7/13/2010 11:09 AM EDT
This entire scenario suggests that Apple needs to review their testing and qualification process. Embedding the antenna in the chassis brilliant? It's hardly brilliant if it doesn't serve the functional purpose. Quality and reliability are really secondary in this market. We have an iPod graveyard upstairs which is testimony to that. I was pleasantly surprised recently when an iPod was replaced by Apple more than 2 years out of warranty because of a "manufacturing defect." As long as phones last to the next phone upgrade, we usually don't care...
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nicolas.mokhoff
7/13/2010 11:59 AM EDT
This antenna stuff all bodes unfavorably for Apple. Consumer Reports, which many consumer follow for smart buying decisions, is not recommending buying the iPhone4 until Apple fixes the "hardware" problem. It's not a matter of adjusting bars in software to suit clear reception.
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prabhakar_deosthali
7/14/2010 1:42 PM EDT
It will now be appreciated if Apple acknowledges the problem, takes its customers into confidence and takes them alon with the solution path it has planned to solve this problem. A feeback/replay to all of us by Aplle spokesperson is in order.
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WSOCT
7/15/2010 11:57 AM EDT
An analysis was made of the iphone 4 antenna problem.
http://idisk.mac.com/rfengr00-Public/web_pics/mw101/iPhone_4_antenna.pdf
Clearly not a software problem. I've heard that very quietly Apple is exchanging customers iphone 4 with an improved "antenna" version. So, if yours is not working try to exchange it.
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phoenixdave
7/20/2010 8:37 PM EDT
WSOCT -- Thanks for posting the analysis. Very well done....
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Tunrayo
7/20/2010 10:29 AM EDT
Now, here is Apple contradicting itself; if the iPhone 4 problem is due to a glitch in the Math responsible for displaying antenna bars corresponding to the level of received signal (RSSI), why have they give out rubber cases to iPhone 4 customers?
Besides, I do not buy the idea of Apple consulting AT&T to determine the best formula for indicating how bars of signal strength are indicated on the iPhone 4g. This type of collaboration is anti-consumer - the air interfaces are standardized and Apple should just display what it measures of the air on its iPhone - AT&T should not be influencing this measurement.
Finally, if Apple maintains it's the Math, then consumers can verify this by testing out a different phone at the same locations the iPhone 4 experiences signal degradation.
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