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iPhone 4 Drops Calls when Left Corner is Touched
- Thread starter dagomike
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Weird, I just tried this exact same exercise on my 3GS with 4.0 and it went from 4 bars to 5 bars?!?! I held it for about a minute too. WTF.
So I'm getting the exact issue as everyone else. FULL signal until I put my hand on the lower left corner then it drops to 0. I used the speed test app to test it's effect on data transfer. These are the results:
Full Signal: 157 kbps Down, 1000 kbps up
Hand on Phone, 0 Signal: 175 kbps down, 64 kbps up
Seems to actually have an effect on signal quality?
Full Signal: 157 kbps Down, 1000 kbps up
Hand on Phone, 0 Signal: 175 kbps down, 64 kbps up
Seems to actually have an effect on signal quality?
I can make my iPhone4 do the same thing, no joke. This is partially a software issue.
I can reproduce it consistently on my 3GS. I have 5 bars when it lays on my desk or when I just pick it up with my left hand. But if I let it dig into the pad of my hand a bit, it slowly drains to 0 bars, then slowly climbs back up to 5 when I put it down.
iOS4.
iOS4.
This is a reductive analysis. The iPhone like any other modern electrical device is far more complicated than simply deducing that the antenna doesn't work.
It's not as simple as a wired connection between the antenna and the screen displaying how strong your signal is. There is serious firmware code to interpret and use the signal from the cell tower. Yes, this may be a huge oversight by Apple engineers, but jumping to conclusions is not helpful. Even if this is a hardware related issue, there are ways to fix this problem with software. Antennas don't just magically work, there is the other end of the circuit that interprets the data from the antenna.
We all want an answer. We all want our stuff to work day one. It doesn't hurt to consider and test other possibilities given how complicated this situation is.
This is absolutely uncalled for, I'm really thinking about cancelling my order over this. If this is a universal issue I think Apple should supply us with bumpers for free, why should we pay for something that is clearly out of our hands no pun intended. This is ridiculous.
the answer is simple. They recommend a bumper. In other words it's a short between the two aerials caused by your hand.
Why not stick a piece of clear sellotape over the affected area so as to insulate the aerials from your hand. This at least means you can use your phone until they finally acknowledge the issue and provide free bumpers.
Why not stick a piece of clear sellotape over the affected area so as to insulate the aerials from your hand. This at least means you can use your phone until they finally acknowledge the issue and provide free bumpers.
I disagree. I believe that Apple knew about this potential issue when they first considered making the antennas part of the external case. The two antennas are not interfering with each other, rather when they are bridged, the impedance changes and it is no longer optimum for it's designed band. This can be compensated for in the signal processing firmware. And we know that they did a lot of work on GSM signal management in iOS4 and/or the DSP firmware.
I think that the known software issue with the signal strength display being incorrect has an unforeseen side effect - that is, if you have an average to poor signal, the display drops all the way to "no signal", iOS thinks you have lost your signal, and drops the call.
This explains why people with strong signals don't see a problem, and why others are reporting good voice and data quality even with almost no bars.
I think a software update will fix the issue.
mine
All I can tell you is what I posted. With Five bars, 3G holding any way, I cannot get the signal to drop. With 2-3 or even 4 bars, I can get it to drop to nearly zero OR zero and lose 3G and go to searching in about 20-30 seconds tops. Doesn't even take a minute. Something is up here with signal strength, or tower AND the external antenna.
All I can tell you is what I posted. With Five bars, 3G holding any way, I cannot get the signal to drop. With 2-3 or even 4 bars, I can get it to drop to nearly zero OR zero and lose 3G and go to searching in about 20-30 seconds tops. Doesn't even take a minute. Something is up here with signal strength, or tower AND the external antenna.
Apple support suggested this for me too but it didn't work. They at least acknowledged that they are aware of the problem and made a genius bar appt for me. Only problem is I have no idea if they're going to have a phone to swap out for mine. I'm going to call ahead of time though before I take a trip to the Apple store.
I hope so. But honestly I can go from 5 bars to 0 in 30 seconds by touching the corner so I don't know how much a software fix can help. My case arrives in the mail today which will hold me over until Apple has some new stock so I can get mine replaced (provided no firmware fix is released).
As a lefty, I can't have a device that does this. It is unacceptable.
I agree with your assesment of the impedence changing when the antennas are bridged by human contact. It also changes the antenna loading capabilities when the impedence is not optimal. Changing the software algorithm to compensate signal propagation will not stop actual call drops nor data connectivity. Apple engineers need to do extensive testing based on our real world experience.
dBm vs bars
Probably some of the different experience are explained by this:
I can display dBm or bars on my iPhone 3GS. Full 5 bars can be from -51 to -91 dBm (-51 being the maximum signal). The range of any phone is from -51 to about -113 where the signal is lost at -113. That's a range of 1,000,000:1.
So full 5 bars is -51 to -91 dBm a 40 dB difference or signal change of 10,000:1
and 5 bars to 1 bar (or none) is only -91 to -113 a 22 dB difference or signal change of 100:1.
This means if you are in a weak signal area, your hand will appear to have a greater influence (100x or less) than if you were in a strong signal area (where you will still see full 5 bars even with a 100x reduction in signal).
The reason is that those 5 bars do not represent the full dynamic range of the phone.
Probably some of the different experience are explained by this:
I can display dBm or bars on my iPhone 3GS. Full 5 bars can be from -51 to -91 dBm (-51 being the maximum signal). The range of any phone is from -51 to about -113 where the signal is lost at -113. That's a range of 1,000,000:1.
So full 5 bars is -51 to -91 dBm a 40 dB difference or signal change of 10,000:1
and 5 bars to 1 bar (or none) is only -91 to -113 a 22 dB difference or signal change of 100:1.
This means if you are in a weak signal area, your hand will appear to have a greater influence (100x or less) than if you were in a strong signal area (where you will still see full 5 bars even with a 100x reduction in signal).
The reason is that those 5 bars do not represent the full dynamic range of the phone.
I've done it 20 times in a row...have it perfected to the exact spot where as soon as I touch, I watch the bars drop 1 by 1 per second...until CALL FAILED
Has to be software...there is no..nO...NO way a company like apple would let such an obvious design flaw go out the door.
Any of us that took elementary science knows a thing or two about current/flow/potato clocks etc.
Has to be software...there is no..nO...NO way a company like apple would let such an obvious design flaw go out the door.
Any of us that took elementary science knows a thing or two about current/flow/potato clocks etc.
yep.....
i had read about the calls dropping... but this morning i was playing around with it some more and pages wouldn't load... got error message so then i stopped touching the left corner (i'm right handed... so i hold the phone with my left hand... DUH!
)i'm not too happy about this right now....
It doesn't take your whole hand cupping the device. It seems like the two antennas being connected via the skin of your finger is enough to throw off the signal. Of course cupping the device will cause it to degrade faster.
Here's a quick video I made (of craptastic quality from my old Flip) showing these results.
http://www.youtube.com/watch?v=GjNtXAOINJk
Here's a quick video I made (of craptastic quality from my old Flip) showing these results.
http://www.youtube.com/watch?v=GjNtXAOINJk
Being a Ham Radio guy, we are taught the importance of antenna impedance. By holding the antenna across a ground (the bottom panel) this surely changes the impedance, and it's ability to receive signal. This seems pretty straight forward to me. I even thought this might be a problem when it was announced at the Keynote.
I still enjoy my phone, and if I don't think about it, it doesn't bother me. Hasn't dropped a call "in the real world" yet.
I still enjoy my phone, and if I don't think about it, it doesn't bother me. Hasn't dropped a call "in the real world" yet.