What the evidence indicates is going on…Sharable Shortlink
On Friday, June 25th, I tweeted a link to a YouTube video created and posted by one of my Twitter followers — @antio — whom I have every reason to believe is legitimate and well meaning. In this brief (53 second) video we see a convincing and rather horrifying demonstration of what appears to be a serious design flaw in the brand new iPhone. For your reference, here’s the YouTube video link:
iPhone 4 Antenna Problem is Caused By a Design Flaw, Not Signal Blockage
Mentions back to me from new iPhone 4 owners were mixed, with some confirming Anthony’s demo and others unable to confirm it and being suspicious of the results.
However, as an engineer I can propose a useful theory to explain what everyone is seeing, and not seeing — and even why Apple shipped the iPhone as it is — as follows:
In other words, say for example that the iPhone is able to deliver a good clear conversation when receiving only 5% of the signal strength that you might have when standing in the shadow of a cell tower. Even though 5% signal strength is far less than 100%, if it delivers a strong and clear conversation, it’s enough. So Apple’s engineers calibrated their digital “5-bars” digital display to show all 5-bars at any signal strength from 100% all the way down to 5%. It’s only when the received signal strength begins to drop below 5% that conversations suffer, calls get dropped, and Apple starts to take bars away from their 5-bar display.
Now imagine that “bridging” the cellular and WiFi antennas by placing one’s hand across the black insulating antenna gap causes a 5% drop in received signal strength. If you initially had, say, 80% strength, now you would be down to 75%… and you’d still have all five bars, since you still have way more than the 5% required for clear calls. Thus, you would see and hear no effect from either deliberate or inadvertent antenna bridging. But if you only had 5% incoming signal strength with the antenna completely in the clear — thus no remaining signal strength margin even though you were seeing 5-bars — and you then bridged the antenna, dropping the signal strength by 5% down to 0% … you would see exactly what Anthony’s video demonstrates.
It’s unfortunate that we don’t have a useful “full range” signal strength display showing us the true received power throughout its entire possible range from 100% all the way to 0% — because I believe there would be much less confusion if people could see what was actually going on. But for now we don’t.
Whatever the case, it does appear that Apple’s latest phone, with its externalized and perhaps too accessible antennas, should be wrapped in an insulating case of some sort in order to not only keep it safe from bumps and bruises, but also to allow its antennas to operate without the attenuation created by direct contact with the phone’s owner’s body.
UPDATE: Don’t miss the comment to this posting by Simon Byrnand who adds some great real world numbers and confirms my engineering theory.
in the old CB radio days my walkie talkie had panels on the side that used your body as an external antenna helping the 12 in one on the unit.Guess 27 mhz could do that.
Actually, the panels allowed your body to become the counterpoise for the antenna. You became the ground plane.
A very rational response.
“It’s unfortunate that we don’t have a useful “full range” signal strength display showing us the true received power throughout its entire possible range from 100% all the way to 0% — because I believe there would be much less confusion if people could see what was actually going on. But for now we don’t.”
Do you have any insight as to why they don’t?
Steve:
Well… <<grin>> all I can say is that “the marketing guys” like having a phone that shows “5-bars” most of the time, even when there’s barely any signal left! Sadly, anyone who “compares bars” on different makes and models of phones is making an entirely meaningless comparison.
On a BlackBerry you can hold the Alt key and press NMLL to change from bars to get a numeric rating of signal strength in -mDB.
NICE! That’s exactly what we need! (I just tried it on my Blackberry Tour and it works perfectly. Cool!)
Before I put up this posting I went searching the iPhone Store for “There’s An App For That” … but there wasn’t!
You can do it on the iPhone by using its “Field Test Mode”
It’s built in and doesn’t need any app!
Susan, the field test mode does not work with the iPhone 4. When I first got my iP4, I was able to touch the bars and lo and behold the db level replaced the bars. After restoring my phone due to other problems, it went away, darn it!
Anyone know how to restore the db reading on the 4?
Is this really such an issue? With the position of the gap you’re unlikely to touch it in normal calling. The real issue should be is it really affecting call quality in normal operation. That’s what I’d like to know, everything else is theory.
Actually, that spot is exactly where you would touch it if you held the phone in your left hand while talking, or while reading mail, etc. The gap between the two antennas would rest comfortably in the padded area of your palm just inside of your thumb. Even if you hold the phone right-handed while talking, there’s a chance your ring or pinky finger could touch that gap. So it doesn’t require as awkward a grip as some seem to think in order to make this problem occur.
That’s an excellent bit of reasoning for why it happens to some people and not others. While there’s no doubt that there’s an issue, I wasn’t sure how to explain this bit.
The sad part, in my mind, is that this won’t prove whose “fault” the ongoing iPhone reception issue is. AT&T or the iPhone device? I’m sure both contribute to the problem, but this little mess is covering up the iPhone’s role in the signal problem, because if the AT&T network is only dishing out 5% signal strength (continuing your example), then the blame still appears on AT&T for having a bad network.
There’s little wonder that Apple produced its own “bumper” skins, cleverly positioning themselves to pretend like this is all a non-issue, while we thank them for being so nice to us. Kinda irks me.
That makes me suggest running an experiment to put an end to this confusion…
If what you say is accurate, then someone should be able to take their new iPhone 4 out, preferably in an open area where the signal cannot be obstructed by any buildings, initiating a phone call while the signal strength is 5 bars and then covering the antenna to reduce the signal, like in the videos circulating the Internet, and seeing whether they can continue the conversation at the same or an acceptable quality.
If we run these experiments a number of times in different locations with the same handset, we should get a better idea of whether the signal loss is truly a significant loss or it’s merely a reporting error.
If it is a reporting error, it raises a couple of questions. Could this be fixed easily through a firmware/software update from Apple? And should expect to see that sometime soon? I would expect this patch would be quite trivial to put together.
For Apple to expose the bare metal of the antenna is just asking for trouble. Antennas are hard enough to design effectively without changing their transmit/receive characteristics and efficiency by allowing contact with external entities. As soon as skin makes contact with the antenna its ability to transmit or receive is affected. In some cases it might be affected in a positive way (properly tuned larger antennas tend to pick up signals better), but generally I can’t possibly imagine that this happens in the majority of cases. Antennas work best when their length and shape have been carefully and properly tuned to the radio frequency they are intended to transmit or receive, and adding the extra (essentially random) size, strange shape, and composition of the human body to the equation generally is only going to cause problems.
In this particular case bridging two of the iPhone’s antennas by the human body is certainly going to cause even more problems. Bridging two radio transmitters into a single antenna is an incredibly difficult thing to do properly without severely affecting at least one of the two radios (usually both), and this is what happens when human skin comes into contact with the two antennas. Since the human body is mostly impure water, it does conduct electricity, and thus radio signals, quite well. Having a hand or finger touching both antennas does effectively create a short across the two. The efficiency and effectiveness of both is dropped dramatically.
Some are saying that adding Apple’s bumper case (rubber band?) prevents the problem. This would make sense, as it removes the potential for the human body to become part of the directly connected antenna. This doesn’t totally isolate the body from becoming a part of the whole radio/antenna system, but it does dramatically reduce its impact, as there isn’t a “direct short” between the two.
One simpler solution would have been for Apple to coat the exposed antenna with some sort of insulating material. Some kind of clear plastic or epoxy would have allowed the phone to keep its styling, while still isolating skin from the antenna enough to prevent this kind of problem.
Think of it this way: the difference in radio energy entering the human body from direct contact with the antenna vs. indirect contact is a lot like the difference in heat you would feel placing your hand directly on a hot pan coming out of the oven vs. using an oven mitt. That little extra space between your skin and the pan makes all of the difference in the world. We shouldn’t be surprised that the antenna stops working effectively when it comes into direct contact with the human body.
Since it seems Apple used a 3G-style disguise on the phone when testing in public it seems entirely plausible that they weren’t really aware of this problem until the phone was released to the public. If this is the case, their testing failed. Which, while discouraging and disappointing, would also not be that surprising. I would certainly hope that the antenna and radio engineers would have known about this problem — I am certainly neither and I know enough to keep antennas isolated from external entities which might interfere with signal reception. But all too often we give credentialed people more credit than they deserve, don’t we.
Ultimately it is a design flaw which probably should have been discovered during the testing phase of the phone. Perhaps if Apple had let Jason Chen keep the phone longer he may have been able to figure this out and let them know before a million of these devices made it out into the world.
Even amongst all of this controversy, it surprised me that nobody is raising a red flag about having up to 0.6 Watts of high frequency radio signal energy being injected directly into the human body (through direct contact with the antenna) being a possible problem. I’m normally not concerned about such things, but I don’t think I’d be quite so eager to subject myself to that as so many people are. We hear talk about possible health concerns from cell phone radiation all of the time, and none of those tests are done with direct contact with the transmitting antenna. Makes me nervous.
Interesting and perhaps possible. I used to be into antennas with my ham radio hobby, and I believe hams used signal strength meters at various locations to generate a map of a signal. I still have a couple of these, though not for the extremely high frequencies used by cell-phones. The transmitted energy of a cell-phone could be harmful, though and distance from the antenna was always the safety model. I’m sure medical researchers are looking into this for all cell-phones and so far the data has been inconclusive, though we do know that it can increase your chances at getting cancer.
i’ve been reading news/posts/info on the Apple iPhone 4 antenna/reception issue AROUND-The-Clock, for 3days straight!.. I have an iPhone 3G and @first couldn’t wait to get the iPhone 4, but now, as this issue has come up, I am greatly reluctant… and i certainly have my reasons why: I spent 70min inside the Apple store, iPhone 4 in one hand, my 3G in the other, and noticed how simply holding the phone naturally (both in my left &right hand) not only caused the bars to go down to zero, but also effected Data transfer speeds. My 3G loaded a Google search w/in 6seconds where as the iPhone 4 didn’t load it at-all!-i seriously had to put the phone down, pick it back up, shake it a little, and try it 2-3 times, and finally the last time, i had to leave it flat on the table without actually touching the phone, in order for it to conduct a simple Google search!) Also, while browsing on Safari, the orientation locked up in landscape mode and no matter what i did, and i did a lot, i could not get it to rotate back to portrait! I then made calls from the phones on display.. the first three phones had extremely poor sound quality. I picked up my 3G, and everything was perfect. Finally the 4th phone on display had voice quality similar to my 3G (or so the person receiving my call stated).
I think i may be falling slightly into the group one person described as persons who are blindly hopeful. As serious as the problem are, and as bad of a red flag the removal of the restocking fee to returns is, I still want to buy the iPhone 4 (can u blame me?-i currently have a 3G!) Regardless, I walked out of the Apple store mentioned above w/o purchasing the iPhone 4-yes, my Priority List name had been called. Today, I got an email from a 2nd store, and instead of being there, purchasing the phone, i’m sitting here writing this comment (short story,heh).
The whole reason for me beginning to write a comment is simply to tell Doug, This [your statement] is the best written statement on the issue i’ve read thus far. Thank you for your input!
Steve,
You’re exactly right about the 1-5 bar reading showing a very limited range of signal strength – at the bottom end of the usable range. This is true of all cellphones, and the bar indicator is only supposed to give a relative indication of likely call quality – any signal stronger than 5 bars whilst stronger, won’t lead to better call quality so isn’t indicated to the user to keep things simple.
From iPhone OS 1.0 through 3.1.3 there was a “full range” signal strength reading available – field test mode, which was a hidden app launched by dialling *3001#12345#* from the phone app. As well as lots of other technical information it would display exact numeric received signal strength in -dBm, (decibel relative to 1 milliwatt) with a range that went far above a 5 bar signal.
To give a sense of scale, -113dBm is approximately the weakest 3G signal an iPhone 3G/3GS can maintain a call or data connection with – this corresponds with 1 bar. -100dBm (13 dB stronger) corresponds to 5 bars, with 2 – 4 bars proportionally in between, so the 1 – 5 bar range is only a 13 dB signal range – a relatively small range compared to the real world range of received signals.
Any signal stronger than -100dBm would still read 5 bars, and if you were within a few hundred yards of a cell tower it’s possible to get a signal as strong as -70dBm (or more) – a full 30dB stronger than the minimum signal necessary to show 5 bars.
In that instance you could have almost a 30 dB loss in signal without the reading dropping below 5 bars – therefore no visible change to the user or dropped call.
From looking at the videos that show the signal dropping from 5 bars to No Service, this means that the person testing it must have only just been receiving a signal strong enough to reach an indicated 5 bars, and the signal must have been attenuated when touched by at least 13dB to reach a point of no service. My estimate is the attenuation is probably around 15-20dB.
So what happened to the field test app, which can display accurate signal strength in decibels over a wide range, and would clear up this whole situation ? It was removed in early beta versions of iOS 4 and remains “missing in action” in the release version of iOS 4, even on older devices like the 3GS.
Sadly, I don’t think this is a co-incidence.
Another factor that may affect how much change different people are reporting is that different countries use different frequencies for 3G – AT&T uses 1900 and 850Mhz, (depending on location) while Europe uses primarily 2100Mhz. (With pockets of 900Mhz in a few countries)
At different operating frequencies the standing wave patterns on the antenna elements will be different, leading to certain points on the antenna being more or less sensitive depending on operating frequency. On some operating frequencies the bottom left corner may be an impedance maximum (voltage point) while at other operating frequencies it may not be. Touching a high impedance point of an antenna always detunes it far more than touching a low impedance point.
It’s not clear what Apple can do to solve this issue without a significant redesign of the casing (perhaps disconnecting the bottom section from the rest of the antenna system leaving it “floating” rather than being connected to the right hand side) or whether people will just have to put up with rubber bumper cases to get the same level of reception as previous models…
Wow Simon!… thanks for the great specific info, as well as for giving my engineering intuition some basis and grounding (if you’ll pardon the pun) in real-world data.
It’s unfortunate that the “secret code” to reveal accurate real-time power-level readings was removed from the final iPhone 4 OS. It seems like a very useful thing to have available. But the down side for Apple is that it would empower people to perform exactly the sorts of experiments that Apple would rather not have performed. And its presence would have just meant more “explanations” needed from Apple.
The whole concept was so sexy though. Isn’t it a bitch when physics interferes with slick industrial design?
/Steve.
I’ve just come across a technical article on AnandTech which absolutely nails this issue – it’s the first in depth technically accurate article measuring and explaining the issues involved, and agrees with yours and my initial suspicions – I highly recommended anyone interested in this issue reads it:
http://www.anandtech.com/show/3794/the-iphone-4-review/2
(Interesting to see that not only is my estimate of 15-20dB loss when held near the figures they actually measured – the actual losses are worse than even I predicted!)
If you jailbreak your iPhone, you can replace the traditional “bar” display with the actual dBm for both cellular and wi-fi. I jailbroke my phone in the past and through multiple restores it carried the setting over to include them even when my phone wasn’t jailbroken any more.
It’s been so long since I originally did it I can’t recall what I did to enable it, but the setting is definitely there. I’m a network engineer and run my own Wireless ISP, so I prefer to have it read directly in dBm because I know exactly what it means without being obfuscated by the “bar” metaphor which I’ve never liked.
What you say is all about the jailbreak and where the data is stored.
If you jailbreak your device and activate all kinds of things visible in the status bar those things are going to be stored in your user data which will be backed up by iTunes.
The rest of the jailbreak is stored in the root of the iOS device filesystem which is replaced by the new firmware.
But the jailbreak data you saved in your user data will be restored onto your new firmware and therefore all status bar changes will appear on your new firmware, too
I hear the Incredible Droid is faster and doesn’t have these problems. This this true?
Only Palm made an issue free phone. All these new ones are like my second wife, all show with no substance.
You can see signal strength by putting iPhone into field test mode. See this article.
http://www.wirelessinfo.com/content/Inside-the-iPhone-field-test-mode.htm
Also, it’s worth mentioning that people using AT&T Micro cells in their house, which should ostensibly give them close to 100% signal can also make the bars go down to nothing and drop a call.
@mactipsdaily
Unfortunately field test mode was removed in iOS 4.0 – for all models of iPhone.
It is still possible to enable the -dBm signal reading on jail-broken devices so if/when we see a jail-break come out for the iPhone 4 we may start to see some actual numbers gathered on this phenomenon.
I’ve not jail broke my phone yet the db signal continues to show even after having upgraded to iOS 4 while using a 3GS. The only thing that changed due to the upgrade for me was that the display of db now shows in a standard menu font instead of a smaller font as it did prior.
Steve, I’m able to reproduce this phenomenon with alarming regularity both in my apartment and at work. When outdoors, however, I can’t make it happen. So I think you’re right that it only happens when signal strength is marginal to begin with, and Apple is doing a disservice to users by reporting a full 5 bars under widely varying signal strength conditions.
Interestingly, there used to be a “field test” app on previous generations of the iPhone OS which you could access by dialing a special code. It would show you signal strength in dB. Apple seems to have removed it from iOS 4. I would imagine that there is no way to access that information using public APIs, so you are unlikely to ever find an app in the App Store which can do so. Maybe on a jailbroken phone?
there was a setting in field test mode to allow the numeric values to be persistent, and if you enabled that persistent values prior to updating to 4.0 *and* updated from a backup- that persisent numeric values remain…..even on a replacement 3gs….
see http://www.flickr.com/photos/10461102@N00/4739732441
Would not help you the iPhones field test mode (if still there in iPhone 4)?
Good explanation anyway!
http://gizmodo.com/277797/iphone-field-test-mode-lets-you-spy-on-the-att-network
Just one thing steve, could you care to give a lesson (on Security now or something) On antennas and wavelengths? Why bridging 2 antennas, and thereby making them into one “longer” antenna make them weaker.
And by the way i CAN draw you that bi-stable multivibrator (loosely translated, and yes it makes the same horrible pun in Norwegian :/) (flip-flop) if you would like :p
I don’t have i4 but on 3G you can do a field test by dialing a particular series of numbers. The field test allows you to view the signal strength in dbs. It is a negative number and the higher the number, the better the signal. For example -68 is excellent and -100 is poor.
The bars indicator in the iPhone is fairly arbitrary. In fact, I remember when the 3G first came out we were all complaining about how the bars were dropping down to 1 or 2 all the time. So what did Apple do? Release a software update that recalibrated the signal strength to cause more bars to display.
I wonder if Apple will take the same approach with the Iphone 4. The only problem is that many have reported a total signal loss when using the “death grip.”
Makes sense Dan… as you imply, “Bar Strength is Marketing.” And that’s sad too, since it’s also useful for engineering and for knowing what’s really going on.
/Steve.
It’s AT&T’s motto not “More bars in more places”?
More bars that mean nothing in more places.
Lol when I worked at BT I heard a new grad (and a multi media degree one as well) say oh 3db’s not much when we discussing sound cards.
Actualy 3db is a lot its over double
Kids today eh
BTW i do have an ex CTO of Motorola in my linked in freinds if you want to do a special on SC I am sure Phill would be up for it
Nobody every buys an iphone because is was a logical choice.
Apple users don’t need good coverage anyway to make phone calls, cause they are to busy downloading applications that make farting sounds.
_______________________________________
Verizon coverage FTW! Android based phones FTW!
dROID we love you
Great you are commenting on this subject, I value your opinion more than the other Steve, Jobs. Please have a discussion in Security now on the next upcoming topic. Eagerly waiting for your Networking series.
Hi,
I wonder if this is just a case of poor QA testing?
What if Apple’s obsession with secrecy was such that no-one took a unit around without a case on it; just to conceal it from prying eyes?
With no-one touching the case of the phone with their hand; was this issue just missed?
Kind Regards
Simon Zerafa
Sounds like a sound theory on scale.
Android Phone readings can be got from going to Menu > Settings > About Phone > Network.
105 dBn 5 asu gave 2 bars on my HTC Desire
Stu
I’m @antio, and I can confirm that I am indeed legitimate and well meaning (:
I’m also an iPhone lover, not a hater by any means. But I do call ‘em like I see ‘em, and it’s hard to not see this as a flaw.
Earlier today I added an update to the description on my YouTube video, explaining the results of some further testing: when this issue occurs, it DID result in slow/failed data communication (browsing, etc), but DID NOT (in some brief testing) result in dropped calls nor even noise nor drop-outs, despite only showing 1 bar of signal.
No body I know of or seen in public uses iPhones without a case, this is a non issue for the majority of the “normal” people, very small percentage of the people trying to make a noise which is not a concern for the general public.
Signed by: suburban house wife/mom
Poor use of anecdotal evidence. Tons of people don’t use a case. But, earlier iPhones had a plastic. This iPhone is a strong glass. A case shouldn’t be needed.
So, how about we take the phone apart and lacquer the d*** anetenna band? 2-3 coats should both do the trick and be sturdy enough, no? Could be a solution Apple could try too, no?
Perhaps not Alan. At these very high frequencies it might well be a problem not only of “conductance” but also “capacitance” and to a lesser extent “inductance” — all things that can screw up high frequency signal propagation. Someone (I’m not an iPhone owner) could easy check this by placing a very thin conductive sheet — a piece of silk or very thin plastic or rubber — over the iPhone 4′s troubled area and seeing whether the effect eliminated or lessened when only “conductance” is eliminated.
I’m thinking of those thin bumpers work, it’s likely conductance, or possibly shorting the two bands together….
And early anecdotal evidence is that Apple’s “Bump Case” does indeed solve the problem, so that’s truly good news for iPhone 4 owners.
All of which leaves me wondering if s simple non-conductive coating might not solve the worst of this issue which I still believe to be one of shorting across the bands. I have no doubt that capacitance and induction play a roll in this, however, we are not likely to eliminate our bodies from the picture any time soon… What we can do is take the shorting out of the picture. I’d try it on my phone, if I had one…
Not to mention the fact that conductance and induction are present on all phones. Let’s also remember that while all phones show drops when held in different ways and all, after all, due to the nature of radio wave physics, moving the phone 1 inch in any direction will completely change it’s reception characteristics at these wavelengths, as with any antenna shorting it out will cause it to, in essence, stop working.
My friend owns a motorcycle custom paint shop, I think I’ll have him spray the antenna surfaces and screw heads on the outer surfaces only when I get my 4g and compare before and after performance. I expect at least a 13-15 db gain at all times when hand held from this.
It seems I was right about this largely being a case of shorting out the antenna. It’s been so long since I studied anything to do with antennas though, I forgot you would need a much thicker insulator than can easily be spray applied. More on the order of 2-3 millimeters thickness at the minimum depending on the material, we want an insulator not a capacitor as the result.
Would be nice to see a software feature that would “baseline” or zero-bar reference a bad connection or call experience. In this day and age, Apple should be able to code some smarts into an S-meter. It’s a relative meter, but relative to what exactly?
How about an app to sample some known data, and use the error rate to recalibrate the meter? Just off the top of me ‘ed thinking.
I’ve not seen these phones yet, but as I understand the reading here is that the antennas are exposed? Cover them with a bit of electrical tape maybe?
why not use old fashioned clear tape? Electrical tape is messy.
I put e-tape along the lower right antenna area, covering all exposed metal. I covered the black strip (break in the antenna) with my palm in my left hand and could reproduce the dropped bar problem. The Addition of the tape did nothing to help.
Don’t know if it’s real or not, but as a spoof it’s genius. As a real product, not so much.
http://awrapforthat.com/
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I think Beck Worley on Tech News Today (June 24) mentioned an article from BoyGeniusReport that this “diminishing bar” problem is also found in older phones that have iOS4.
The article I was referring to is iOS4 Reception Issue is Looking More Like a Software Bug at the BoyGeniusReport.
i upgraded my iPhone 3G to iOS 4.. then i ran across a youtube video that showed 3G and 3GS phones dropping bars like the iPhone 4.. i death-gripped my own 3G and saw the bars dropped..!
for other reason (iOS 4 too much for the 3G), i downgraded back to 3.1.3 (or whatever)… i death-grip my phone now-and the bars don’t drop @all!.. keeping my fingers, toes, &nose hairs crossed!!!~i hope this IS* simply a software issue (although it only logically seems like a hardware one!).. but the facts i stated above are just that!
***hoping for the best!!… Apple/iPhone-DON’T FAIL ME NOW!!!!!!!! :-/***
What about when multiple phones are tested in one location and only certain ones are doing it? They should be getting the same signal strength?
Steve,
Thank you for interesting post. Here’s not quite related but still interesting article by Mike Elgan – iPhone 4: Triumph of the design nerds http://goo.gl/CblM
iPhone 4 antenna problems were predicted on June 10 by Danish professor http://tinyurl.com/285ubz2
(disclaimer: I don’t have I Phone 4, but think it’s a wonderful device)
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I can stand feet away from the AT&T towers on my parking garage, touch the antennas and lower the bars. I don’t think I’m starting with a diminished signal.
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I can reproduce this on my iPhone 3GS running iOS4. Of course I didn’t try it when I had iOS3 so I can say for sure it didn’t happen then, but it looks like a bug in iOS4 to me.
THAT would sure be great! Then it would just be a brief first-adopter glitch which would soon be forgiven and forgotten.
/Steve.
i agree!, i have written above:
i upgraded my iPhone 3G to iOS 4.. then i ran across a youtube video that showed 3G and 3GS phones dropping bars like the iPhone 4.. i death-gripped my own 3G and saw the bars dropped..!
for other reason (iOS 4 too much for the 3G), i downgraded back to 3.1.3 (or whatever)… i death-grip my phone now-and the bars don’t drop @all!.. keeping my fingers, toes, &nose hairs crossed!!!~i hope this IS* simply a software issue…..<
I was watching a profile of Benoît Mandelbrot recently and they said that modern cellphones used antennas shaped like fractals, which allowed them to receive multiple frequencies. They even had pictures. Has Apple abandoned this design, or am I confusing two different things? (It wouldn’t be the first time
I don’t have a phone to test, but it seems like a piece of regular clear tape should fix this problem.
Of course, someone will come out with a fancy looking piece of tape, name it iFix and charge $50.
I think this gets at it and a very important lesson: always know how your test instrument is calibrated and how to read it. Unfortunately, in iOS4, no one seems to know (especially without field test mode). My guess is that the forthcoming 4.0.1 update will recalibrate the meter… Not that we’ll be any the wiser. The non-problem will just become invisible.
For my part, my iPhone 4 gets much better reception than my iPhone 1, no matter how I hold it.
I would like to recommend this short article by Spencer Webb from Antenna Sys Inc. He discussed this iPhone 4 antenna problem and why the FCC’s requirements caused this to happen.
http://www.antennasys.com/antennasys-blog/2010/6/24/apple-iphone-4-antennas.html
It is a good read. He presents a complex technical issue in an easy to understand way for laypeople, just like Mr. Gibson does.
Hmmm….
Spencer’s latest post, and a follow up to his first excellent analysis, mentiones Mr. Gibson and this post!
http://www.antennasys.com/antennasys-blog/author/antennasys-inc
He is a fan of Steve. Great minds think alike.
Thanks for the heads up about Spencer’s work on this issue, Ron. Spencer makes a number of really good additional points too. His reminding us that the bars are controlled by SOFTWARE being, I think, the most significant. That software could have any “agenda” it wants … and we’re left guessing.
Sounds like you’re saying the bar indicator shows the “last” 5% of the useful signal strength. If touching the phone reduces the useful signal strength below 5% (down to zero) does it really matter how strong the signal was prior?
The video shows the signal strength going from (the last) 5% down to nothing on a brand new, $500, touch controlled device- just by touching it.
Guess we found a new use for duct tape.
I had the same understanding as JGBlake. I thought cellphone antennas had long since switched over to fractal antennas.
A modern smartphone deals with at least four ranges of frequencies I can think of – cell freqencies, wi-fi, bluetooth, and GPS. Did I forget any? Well, a fractal antenna repeats the same pattern at several different scales, and as a result is “tuned” to a wide range of frequencies. So the same antenna can be used for all of the frequencies the phone uses.
But now Apple has reverted back to a tuned length of metal, which I think means there are now four separate antennas. Well, actually, I don’t know that. The metal band could be just for the cell frequencies, and there could be another (fractal) antenna inside the case for the others.
I’ve always wondered if the hate campaign (Molly rants, etc.) against AT&T was fully deserved. I keep hearing stories about other AT&T phones, including smart phones, make calls just fine in the same room where iPhones experience dropped calls. It’s just not clear to me exactly where the blame lies for the iPhone problems on AT&T.
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Just wear those rubber gloves some people use when washing the dishes, then at least the phone still looks great
AT&T uses two different frequencies bands (850 & 1900). My theory is that the shorting of the iPhone 4 antennas at the lower left corner causing a detuning that only affects one of these frequency bands. Thus why some users cannot replicate the issue. Their specific location is not serviced by the affected frequency.
As it is breaking in Europe and (a friend currently in Dubai informs me) in UAE too.
I do ‘enjoy’ the whole theory that holding any phone can cause such issues, I fully enclosed four different cell phones in my hands and still got bluetooth to work AND didn’t drop the call quality, let alone drop the call. However, the one finger grip of death to a friends new iPhone 4 almost had him claiming on his ‘accidental’ insurance cover for the thing when he considered throwing it out of the window
Can anyone explain this? On my iphone 4, this appears to be a transmission only issue. When the band is covered by my finger, my wife (in my house on a landline) cannot hear me. Interestingly, when she talks, not only can I hear her but it seems to temporarily “wake up” my transmission and she is able to hear me until my voice fades to mute again.
http://conversations.nokia.com/2010/06/28/how-do-you-hold-your-nokia/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A NokiaConversations-Posts (Nokia Conversations – Posts)&utm_content=Twitter
Lol! Nokia says go ahead and grip your phone anyway you want – no signal degradation. Apparently they know something about designing cell phones.
The whole bare, external antenna idea is a mess. A real, full scale signal meter would help immensely in showing the effects when the iPhone is held at various places.
Assuming their software fix isn’t just some smoke and mirrors rigging of the interface’s signal meter to give the iPhone 4′s the impression that they’ve fixed the problem (something that will be scrutinized the tech community to a fair-the-well), Apple my be able to somehow mitigate some of the antenna issues with a software update, but I doubt it. And they certainly won’t be able to fix it right that way.
The main issue here is the poorly conceived design choice to have the user’s body (hand) come in direct contact with the bare antenna elements. By doing so the user’s body becomes a part of the antenna circuit. Some sites posit that some of the iPhone 4′s were mistakenly shipped lacking a clear insulating coating on the case frames/antennas. If so, a great deal of them were shipped as such, but I doubt this claim. Reason being, Apple’s choice of material for the frames. Stainless Steel is chosen by product designers precisely because there is no need to apply a finish (paint) to it. If Apple intended to apply an insulating finish to a metal case-frame that doubles as an antenna, they would have been far better off to use aluminum because it’s cheaper by far, a far better RF conductor than stainless steel and it holds a finish far better. SS is hard to keep a finish on and why would you bother?
Antennas are sized and cut to precise lengths to match their intended resonant frequencies in wave multiples. By touching the bare antenna element you effectively change its physical properties and hence, its frequency, and too, adding other interference such as grounding and turning the antenna’s energy into heat in the user’s body in varying degrees based upon so many unknowable variables that it would be a mind-numbingly complex matter to compensate for them all in software, and you could never fix it all.
When considering the user’s relative conductivity everything then comes into play from the PH (acid or alkaline)of the users sweat based on their diet (low salt diets for people with high blood pressure will have sweat that is likely less conductive), the weather (rainy or dry), relative humidity, where they are (standing barefoot on wet grass or sitting in a bathtub, touching other metal, grounded or not), the variables that must be dealt with become exponentially increased to—infinity.
This condition exists in varying degrees anywhere you touch the case frame but the likely reason that it is most pronounced at the insulating joint between the antennas at the lower left hand of the device, is because one or both of the antennas are connected to the logic board there, creating the greatest bridging of the two antennas where they then cancel each other out to the greatest degree at that spot. Stainless Steel is a relatively poor electrical conductor so the further the user’s hand gets away from the connection points the more resistance is introduced into the antenna circuit making the bridging less pronounced. Though, still, whenever the user is in contact with both bare antenna elements (both case frame sides) there exist some bridging of the two antennas.
The bumper case fix works effectively precisely because it breaks that antenna/human circuit, insulating the user from the antennas. At that point all of the well known variables related to RF signal propagation come into play and can be compensated for fairly well in software. All RF (Radio Frequency) device and cellphone makers have been dealing with this very thing since the advent of radio. There are reams of literature on this subject. I even have a bunch of hardback volumes on RF circuit and Antenna designs in my own modest library. So, when Apple says that there is always some attenuation that occurs when people hold on to any cellphones with their antennas insulated or isolated by mounting them within the case, that attenuation is caused by the person’s body mass blocking the signal. There’s a big difference blocking signal and shorting it out in various ways by the user coming into contact with the antenna elements. Slick marketing can’t change the laws of physics.
I don’t know what Apple has planned in their software update, but if they don’t have a way to physically disconnect whichever antennas is not currently in use, they’re not going to have much luck. Even so, as you can see from the above explanation, it could only provide a partial fix.
Plus, if Face Time uses both the wifi and 3g antennas simultaneously (being able to join while in a normal call), that’s going to involve quite another trick entirely.
Latest rumor: Apple was going to release an app to fix the reception issue. After you installed the app, when you touch the antennas, the phone will send you a mild electric shock or vibrating alert to remind the users “Just avoid holding it that way”. It also announces “Hey my name is Steve Job, you should just avoid holding it that way” if you want to use this revolutionary iphone 4.
This app is completely customizable and it will cost just $4.99.
@iphonefanboy,
Your comment is definitely the best!
The field test phone number doesn’t work on my 3GS running 3.1.3. I used to be able to access the data by dialing that number on my 3G, but I don’t think I ever tried it on my 3GS. It’s possible it was never able to connect, or an update to the OS removed that ability somewhere along the line.
The very idea of software manipulation of signal strength indicators feels deceptive. I wonder if the FCC has anything to say about the issue?
I tried the number again and it does work on my 3GS. Testing without my silicon case, I can see signal strength drop if I hold the phone in the “death grip.” Went from -95 to -113. So the situation is not unique to the iPhone 4.
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I beg to differ about those having 3G Microcells in their homes being able to trigger the same effect. I have one sitting near my window, as recommended, about 6 feet from my computer. Try as I might, put my fingers where I may, I can do nothing to make the five-bar signal decrease in the slightest. I had begun to think that this was all in some people’s minds, but then at the YMCA, with a five-bar (but I suspect just above the five percent level) signal, I was finally able to see what people are talking about. I’m going to get some kind of case.
For the Nokia lovers:
http://www.businessinsider.com/nokias-instruction-manual-2010-6
http://www.youtube.com/watch?v=amPG52DVQuk
The thing is, this “Apple problem” seems endemic as long as we have these frequencies to deal with, and people unwilling to extend antennas before they talk. We might be able to reclaim some parts of the former analog television frequencies, which are much more robust in penetrating walls.
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I think you make an excellent point Steve.
Another thing that I think could explain why people are getting different results is moist. Some people simple sweet more or live in more moist environments, and that might make them more conductible than others.
Disclaimer: I haven’t read all the commenst, so I apologize in advance if I’m going to repeat what someone else has already said.
I have an iPhone 3G and the iPhone 4 won’t be available here in Italy until late July, or so they say. (I actually think that it will be postponed well into the fall, considering the huge sales in the countries where it’s already available, and these issues. They might end up having to recall the units indeed.)
However, I have noticed that my 3G with iOS 4 does indeed show more bars than it used to. In my room/office, I used to get an average of 2 or 3 bars on 3G, 5 on GPRS, and I’d seldom get EDGE. Now it’s 5 bars most of the time in any configuration. Incidentally, I can make it lose 2 or 3 bars by tightly holding it in my right hand, as to cover the lower-right corner (which is where the antenna is on the iPhone 3G.)
I am wondering how this whole thing will end. It may be something that can be curbed by a software update, but the issue of shorting antennas is there. I am however wondering: does it happen at all if you touch the two antennas at different, more distant points? After all, that’d still be a short.
As a sidenote, if/when I get mine, I’ll get a bumper anyway. Considering how fragile the double glass is, some protection is better than nothing. (Of course, I hope that other manufacturers come up with better and/or cheaper rubberbands.)
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Can someone explain to me why the WiFi isn’t being affected?
If the problem is as you say and is because of an initial poor signal then it makes the most sense why WiFi won’t be affected as you’d generally be in a good WiFi spot but no one has ever pointed out WiFi issues which I found to be interesting. If it was a hardware issue then it would seem to me that bridging both antenna would kill both signals.
This has now been carefully studied and it looks like Steve’s surmise was correct:
http://www.anandtech.com/show/3794/the-iphone-4-review/2
More importantly, and almost lost in all the carrying on about hand position, “It’s amazing really to experience the difference in sensitivity the iPhone 4 brings compared to the 3GS, and issues from holding the phone aside, reception is absolutely definitely improved. I felt like I was going places no iPhone had ever gone before.”
You conveniently left out the first sentence in that Paragraph:
“With my bumper case on, I made it further into dead zones than ever before, and into marginal areas that would always drop calls without any problems at all.”
The comment about better reception than previous iPhone models was specifically made in the case of the rubber bumper case being fitted, not without.
Do you mean to think that the case is adding to it’s ability to receive a signal? I’m not following you here. Presumably, it would be just as able at getting a signal in a holster (as mine is most of the time when not in a car), sitting on the passenger seat (as mine does most of the time when driving) or sitting in a dock connecter or even when gripped in the right hand or in any way that does not short the two antennas.
Now that I have my iPhone, I’ve found this entire debate to be a non-issue for me, I get consistently better coverage with my device and it is naked of a bumper or other case, save my holster (see above.) With all this talk of bumper cases, another simple solution, and one many people already employ seems to do the trick. Use a bluetooth or a wired headset. If not for all the news hullaballoo, I would never have noticed a problem with my iPhone 4.
While I do think this is a design flaw and I expect a rev 2 iPhone will be in the near future, it’s not the end of the world. Dear Gawd, you should have had a motorola starTac, or any number of other phones since that have been truly bad.
And you, Simon, conveniently left out the last sentence in the next paragraph
“. . . I couldn’t make calls drop driving around an entire day cupping the phone, despite being at -113 dBm (1 bar) most of the time.”
He earlier defines cupping, one of the five positions he tested, as “the absolute worst case,” squeezing the naked phone, with a sweaty palm, so hard “it’s physically painful.”
So unless I’m missing something I think we can reasonably conclude that apart from the misleading signal strength bars he couldn’t find a practical problem with the iPhone 4′s reception, and in fact found it far better than previous iPhones, with or without a bumper case. That has been my experience so far as well. As Anadtech says, there does seem to be a flaw in the new external antenna setup, but its practical significance has been wildly exaggerated since the phone as a whole works great. It’ll be even more great once they address that antenna flaw, whether via a software or hardware revision.
So… only a problem if you are left-handed?
Maybe Apple should make a left-handed version of the iPhone.
Only a problem when “left handed”? Honestly – most righties -myself included – hold the phone in the left hand (right is used for pushing buttons n’ stuff)
/Z
Now, there’s an idea for an iphone app. One that would actually show you the real signal strength but we all know that isnt going to happen since apple wouldnt allow it in a million years. This underscores the difference between the android marketplace and apple’s app store. If that had happened on an android phone, someone would simply create an app that would easily integrate with the rest of the OS and give you a real, more accurate reading.
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Knock knock
Who’s there?
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Apple on iPhone 4 Antenna: It’s the Bars, Silly http://bit.ly/ca0bW6
So, they are explaining it pretty much the same way Steve did above, but obviously it’s not satisfactory.
I thought this made interesting reading. Initial (albeit basic) tests suggest the iPhone 4 is no more affected by this issue than the original iPhone…
http://www.antennasys.com/antennasys-blog/author/antennasys-inc
Looks like Apple is now blaming it on a “faulty signal strength algorithm” in the iPhone OS as Vladimir said. That confirms everything Steve said. Seeing them lie about it and claim it was an accident is typical Apple style.
http://www.nbcbayarea.com/news/tech/Apple–97663404.html
I don’t think they lied about it I think they needed time to confirm the issue. Anyone who’s ever done hardware support and found an issue that’s never been seen before will rightly tell the user to not perform that function or not perform it that way until we come up with a fix. Apple did the same and it seems the fix was quite simple.
Can Apple fix the signal drop issue? Not with the phone in its current state because they’ve done what they had to do in order to fit everything in. Apple also can’t fix something that is a result of physics. As much as all the Apple fanboys like to think Steve Jobs is God he isn’t and so he’s bound by the laws of physics just like the rest of us. The fix for the signal issue is to simply get a case. Does it annoy people that they have to do so? Initially but most people use cases anyway and the bumper cases are really quite nice.
Steve Jobs was well within his rights to say if you’re experiencing the issue holding the phone one way then don’t hold it that way. Was it blunt? Yes but then some people need to be told things bluntly because they clearly don’t understand the issue.
If your kid came up to you and said “Dad, when I hold the knife by the blade I cut myself” doesn’t it make sense for you to tell him not to hold it by the blade? Yet when Steve Jobs says it everyone thinks he’s an idiot. Why is that?
Darryn-
Your analogy – “If your kid came up to you and said “Dad, when I hold the knife by the blade I cut myself” doesn’t it make sense for you to tell him not to hold it by the blade?” – is not quite right. It would be more like:
“Dad, when I hold this new knife by handle the way I’ve always held knives, I cut myself”. Dad would probably tell him not to use that knife anymore or maybe to put a plastic bumper around the handle.
@Darryn
There is a problem with your analogy. The kid is holding the knife by it’s handle, the way it’s supposed to be held and using it properly but even then he gets cut. When they designed the iphone 4 I’m sure they didn’t just say “Oh well let’s just design an antenna like that and not do any testing because i’m sure it’ll work.” There is a lot of testing involved in antenna design both for the consumer side and for the government regulators. I’m 100% sure they knew exactly how the reception on the phone would be and what kinds of things could affect it. They made 2 mistakes. First, they became arrogant and thought they could simply get away with it. Apple didn’t expect the reaction this issue would get. Second, because of that arrogance they tried, as usual, to spin this as a trivial problem when in reality it was a very real and serious issue. 2 years ago Apple would’ve gotten a pass but now they’re under intense pressure from other phone manufactures in the market to perform. There wasn’t an alternative 2 the iphone 2 years ago, now there are very compelling and arguably better phones out there that could make your decision not to buy it a lot easier.
There is still another thing that really was unapple-like which, in my opinion, reinforces my belief that they knew about this issue before the phone was released. It’s the sale of covers for the phone they spent enormous ammounts of time and money designing to be beautiful so it could just be covered.
No the analogy is right. The problem is caused by holding the phone in one way. Therefore the problem only exists in one method of use. This is the same with the analogy because if you only cut yourself holding the knife one way then it stands to reason that you hold the knife a different way.
Seriously I’ve paid particular notice of how I hold my iPhone 3G to see if when I upgrade I’ll have the same issue and I cannot comfortably hold the phone in such a way so as to cause the problem. Therefore it seems simple… don’t hold it that way.
The Register: Apple’s iPhone 4 denial: insulting or ignorant? http://bit.ly/9y1cbJ. A very good article.
Well, if you trust The Register…
More seriously, if the new antenna is more sensitive, is it not more sensitive to interference and attenuation?
The short answer is: The more sensitive the antenna, the more everything it picks up, including, yes, interference. It is then up to the discrimination power of the radio to weed out the good from the bad. To ‘squelch’ the interference.
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Hi Steve,
Am watching your comments on TWiT 255 on the antenna debacle and if you’ll excuse the digression – what the heck are those interesting Lost in Space style blinky boxes on the shelves behind you? I think I need some props like that (ideally they’d be only the front for something useful but one thing at a time). Please, do tell! Cheers.
The fact is most calls are dropped because there are too many devices on too few towers and not how far away from the tower you are. As a couple of different engineers I have heard have stated, signal strength is not a good indicator. Signal to noise ratio is far more important. Even if you have close to 100% signal it doesn’t mean much if you have a lot of people all using the same tower. The indicator should also take into account error rate. Maybe if the bars turned from green to red or if SNR was an offset against signal strength we would have a much better representation of how likely you are to drop a call.
Interesting reading, Steve’s replies are more interesting, possibly sense I am a fan of his show Security Now. wisewarrior in twit irc.
Hey Steve, if you don’t want to wait forever for a Firefox restart because of your numerous tabs take a look at “BarTab”. It’s an add-on that prevents your tabs reloading on a restart until you need them (when you click on them). Should speed things up for you when firefox updates.
Sorry about posting this exact same thing as a comment to your first blog post, I promise this’ll be all the spam you’ll get from me on this matter. Just wanted to make sure you saw it.
I love hearing your show, “Security Now”.
This is off-topic but I didn’t know how else to reach you.
I think you’ll be interested in this new open source security software, download available in August. He’s also selling a router type box with the software installed on it.
I think you ay find John Flowers a kindred spirit. He’s a one-man company (I think), and very productive.
Link to white paper.
http://kane-box.com/docs/kanebox.pdf
He just updated the FAQ, but the white paper has the most info. Here’s a quote from it:
“The initial release of kane|box is designed specifically to replace your firewall or wireless router.
In addition, kane|box will:
- Perform Network Address Translation (NAT)
- Perform DHCP on your network.
- Get an IP address from your ISP (automatically).
- Perform VPN and allow you to connect (remotely) to your network, through your ISP’s IP address.
- Provide Logging and reporting for all connections, attacks and exposures.
- Block viruses from being downloaded/uploaded to/from your network.
- Scrub incoming and outgoing attacks.”
I hope to hear your opinion on what he’s doing and what you think of his plan of attack.
Peace, Love, Laughter,
Rob:-]
On a more hilarious side is an alternative workaround;
You can buy a cool sticker that can cover the problematic area on the side of the iPhone, at least this solution seem to have a sence of humor
http://www.etsy.com/listing/52058857/iphon-end-call-now-sticker-stops-signal
Another thing all together is, why is it harder to create a white iPhone than a black one!?
“Statement by Apple on White iPhone 4
White models of Apple’s new iPhone® 4 have continued to be more challenging to manufacture than we originally expected, and as a result they will not be available until later this year. The availability of the more popular iPhone 4 black models is not affected.”
Industrial Furnace manufacturers | Industrial Oven manufacturers
I think i could sit for hours browsing around this site, because there’s no end to the information. But i found a gem i would love to hear more about, and that is *Netfilter*.
I found an extensive article at your page about this thing, and that it shiuld come out as soon as possible, and that *ShieldsUp!* also was about to get updated quite soing like thaton.
Then i had a look at the bottom of the page, and saw that it was last updated in 2002, or something like that. Is a technique such as Netfliter still usable today? What is going on? Is Steve Gibson Research about to pack up and close it’s doors?
I have’nt been to your page in about 6 years, but stumbled upon it after a search for a way to test my firewall.
I’m sad to say i’m not impressed, even though you have accomplished alot in the past, but what’s going on now?
Internet and the world of computing needs people like you, who are not afraid of taking the risks or thinking outside the box.
So I’m listening to your most recent Security Now and you’ve made me think of the Force TLS addon for Firefox. Check it out if you have the time.