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jdee2wheels

macrumors regular
Original poster
Aug 15, 2007
111
42
I've had my iphone 4 now for about a week and like many have suffered from reception issues related to bridging the lower left side antennas on the phone. What's very odd however is that so far I can only replicate the problem at my house. Here's the situation:

At Home:
I'm literally 2 blocks away from what I believe are the ATT cell towers for our area. I have full bars almost all the time with both the iphone 4 and the 3gs I still have. On the iphone 4 I can immediately drop the signal down to 1 bar by just holding like I normally would. If I deliberately bridge the antenna in the lower left I can get the "no service" indicator within a few seconds. This is 100% repeatable all the time and it's a big issue because I can accidentally drop a call if I'm not paying attention to my hand position.

At Work:
I'm in an office complex with a cell tower about 1/4 mile my window. I get full bars all the time. However unlike at home, no matter what I do I can't get the phone to drop even one tick of signal. Even deliberately trying to bridge the antenna does nothing.

I realize the signal bars are just an approximation of the signal so I may in fact get better reception at work, but I find it odd that the bridging issues are completely gone in one location, and 100% repeatable when connected to a different tower. Is it possible that some cell towers cause this problem and others don't?
 
I've had my iphone 4 now for about a week and like many have suffered from reception issues related to bridging the lower left side antennas on the phone. What's very odd however is that so far I can only replicate the problem at my house. Here's the situation:

At Home:
I'm literally 2 blocks away from what I believe are the ATT cell towers for our area. I have full bars almost all the time with both the iphone 4 and the 3gs I still have. On the iphone 4 I can immediately drop the signal down to 1 bar by just holding like I normally would. If I deliberately bridge the antenna in the lower left I can get the "no service" indicator within a few seconds. This is 100% repeatable all the time and it's a big issue because I can accidentally drop a call if I'm not paying attention to my hand position.

At Work:
I'm in an office complex with a cell tower about 1/4 mile my window. I get full bars all the time. However unlike at home, no matter what I do I can't get the phone to drop even one tick of signal. Even deliberately trying to bridge the antenna does nothing.

I realize the signal bars are just an approximation of the signal so I may in fact get better reception at work, but I find it odd that the bridging issues are completely gone in one location, and 100% repeatable when connected to a different tower. Is it possible that some cell towers cause this problem and others don't?

There's been a good amount of speculation that the issue is somehow location based (meaning - based on strength of signal).
 
Possible, waiting for someone to come in and spew the

"Fundamental hardware flawz!"

I really wish the mods of this forum would clean this place up and migrate ALL reception related posts into ONE GIANT THREAD.

This forum is a mess IMO.
 
Not only possible, but highly likely in fact. In conjunction with some baseband tweaks in iOS4 by Apple, AT&T has been rolling out a change to tower hardware/software that is believed to be related to this issue. This change was not fully implemented (i.e. not all towers updated) when iOS4 was released.

Now I may well be here in a week or two sitting down to a large serving of crow but I'm willing to bet heavily that this issue can and will be addressed in software, not with any kind of IP4 recall or replacement campaign.
 
Not only possible, but highly likely in fact. In conjunction with some baseband tweaks in iOS4 by Apple, AT&T has been rolling out a change to tower hardware/software that is believed to be related to this issue. This change was not fully implemented (i.e. not all towers updated) when iOS4 was released.

So AT&T is fixing an issue with the multiple networks in 5 different countries that offer iPhone 4?

They sure are busy.
 
It could certainly be tower position, relative location to tower, the frequencies of the tower, or the phone reacting to other towers/signals.

It could be possible if ATT (or the companies it has eaten) is an incumbent wireless provider you may have access to different spectrum, and thus perform differently.

Not sure, however, you explain problems with MicroCell, unless the problem is related to the 1900 MHz spectrum, and that's what problem areas happen to be using.

One constant, however, is the iPhone 4 appears to suffer significantly more than other devices.
 
Is it possible that some cell towers cause this problem and others don't?

There are all kinds of differences between cell towers in different locations. Every cell carrier uses more than one vendor or supplier, and over the years have built base stations using different equipment and different manufacturers as time has passed and contracts change hands. It's possible to have old-generation Lucent equipment in one location, newer Alcatel-Lucent stuff in another, Nokia in some other place, etc.

Even if you had two base stations using exactly the same gear in two different places, they're going to behave differently. Antenna panels are tweaked for optimal aiming based on the environment they're in. CDMA and WCDMA/UMTS/HSPA cells "breathe" differently in different places, altering their power levels based on how many users are in an area. And a lot of times they use different frequencies. It's even possible for AT&T to have 850Mhz in one town and 1900Mhz in the next town over due to licensing.

So yeah, all of this stuff can affect how any phone interacts with the network.
 
There are all kinds of differences between cell towers in different locations. Every cell carrier uses more than one vendor or supplier, and over the years have built base stations using different equipment and different manufacturers as time has passed and contracts change hands. It's possible to have old-generation Lucent equipment in one location, newer Alcatel-Lucent stuff in another, Nokia in some other place, etc.

Even if you had two base stations using exactly the same gear in two different places, they're going to behave differently. Antenna panels are tweaked for optimal aiming based on the environment they're in. CDMA and WCDMA/UMTS/HSPA cells "breathe" differently in different places, altering their power levels based on how many users are in an area. And a lot of times they use different frequencies. It's even possible for AT&T to have 850Mhz in one town and 1900Mhz in the next town over due to licensing.

So yeah, all of this stuff can affect how any phone interacts with the network.


I guess the follow up would be, if the phone behaves perfectly at one cell tower, and poorly at another, is this something that can be fixed with a software update, or is the phone design flawed to begin with. I'm sure this is the question that everyone wants to know the answer to :). Lets hope the answer comes before many of us have to decide if we need to return the phones.
 
Given that any issue is going to be entirely within the baseband code - it could be that the handling of some frequencies is weaker than others ... the iphone is a penta-band device and its meant to be capable of switching frequencies ... so if your home tower is a 1800mhz one and at work its a newer 850mhz one it might be the way the iPhone is dealing with signal bands

Who knows ... Apple hopefully and they'll either continue to deny or release an update in due course .... we can do little

People who think 'ZOMG!!! Hardwarz is borken! Refund NAO!!" should do just that ... take the device back and leave ... i'm being patient as i seem to be ok 99% of the time (can't seem to replicate issue in certain locations also)
 
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