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New theory on antenna issue: It's the towers?

Vertigo50

Vertigo50

macrumors 65816
Original poster
Apr 11, 2007
1,200
132
Okay, so I know a lot of people are saying they have not had the problem at all, and others are saying they ALWAYS have it. I had thought the people who never have it might have gotten a phone that isn't affected for whatever reason. Some people have guessed it is based on signal issues, but one person tried it directly under a cell tower and still had it happen.

So I have a new theory: I think the problem is definitely the phone, but it also has to do with the TOWERS. I think some towers respond okay to the phone, or compensate, while others don't. I'm not saying the phone isn't doing something weird, just that certain towers cause a loss of signal and others don't. Here is why I think so....

I have about 4 to 5 bars in my home office. I can make the phone go to 1 or 0 bars EVERY TIME I bridge the two antennas, even barely touching it with one finger.

BUT, I just went to a busier part of town tonight and tried it, and no matter how much I gripped it or touched it, I could not get it to go lower than 5 bars.

Obviously, the signal is stronger in this area, but as I said, someone had tried this standing directly under a tower, and was still able to do it. I think that if I found the tower near my house, I could probably get it to lose signal, but no matter what I do, I can not get it to lose signal in the busy part of town.

It could even have something to do with towers that overlap? Maybe it is able to switch to another tower and not lose signal?

What do you guys think?
 
I spoke at length with AT&T today. My tower, about 900ft from the house has 2 3G "pods" she called it with a 3rd to be added on August 12th.

I get great reception, nearly every drop call is on full bars.

The thing is this, the calls just drop or go silent, there is no break up, fading, none of it, it just stops.
 
It's definitely the towers. I can easily replicate dropped bars in my apartment but at work it is ABSOLUTELY impossible. This led me to come to the same conclusion as you.
 
Turned off my 3G and my reception issue stopped. I also had alot of fluctuation in signal strength/bars as well as the death grip phenomena.
 
iPhoneHome said:
It's definitely the towers. I can easily replicate dropped bars in my apartment but at work it is ABSOLUTELY impossible. This led me to come to the same conclusion as you.
Click to expand...

Part of my next phone call to AT&T will to be to send me a microcell and discount the amount off my phone.
 
Eric-PTEK said:
I spoke at length with AT&T today. My tower, about 900ft from the house has 2 3G "pods" she called it with a 3rd to be added on August 12th.

I get great reception, nearly every drop call is on full bars.

The thing is this, the calls just drop or go silent, there is no break up, fading, none of it, it just stops.
Click to expand...

This, exactly, has been my biggest issue with the phone. I don't care about the bars dropping, it's that I'll drop calls (a lot of calls) while having 3-5 bars and good reception.
 
Just to be clear, I am NOT blaming AT&T.

Do you all remember in the keynote or somewhere, they were talking about how they rewrote the baseband or the software to use a different method of choosing a signal? Something like it would choose the signal with the least interference instead of the strongest?

I am starting to think that what is happening is when you bridge the antennas, it triggers some kind of "switching" in the phone or something. This obviously shouldn't happen, and is a flaw with the phone or the software.

But what I'm speculating is that maybe some towers are able to compensate for this, or their signal is strong enough to overcome it, while others are not.

In other words, I think it's a flaw in the hardware or software of the phone, but that maybe the tower you're connected to makes a difference too, which is why some users are having the problem and others aren't.
 
The reason you won't find it anywhere is pure strength of signal. Attenuation occurs when that part of the antenna is covered. Attenuation is sort of if you put on sunglasses, the sunlight is attenuated because of that.

If there are plenty of towers and they can handle the attenuation caused by your hand over the antenna, you'll probably be fine. There are also other mitigating factors like what type of structure you're in etc.
 
i-John said:
The reason you won't find it anywhere is pure strength of signal. Attenuation occurs when that part of the antenna is covered. Attenuation is sort of if you put on sunglasses, the sunlight is attenuated because of that.

If there are plenty of towers and they can handle the attenuation caused by your hand over the antenna, you'll probably be fine. There are also other mitigating factors like what type of structure you're in etc.
Click to expand...

I would agree with that, except that one guy tried it standing directly under a tower, and still had it happen. How do you explain that? A tower designed to cover blocks and blocks doesn't have enough signal to go through your hand?

In fact, if a cell signal can get through walls and other obstructions, attenuation of my hand shouldn't be enough to lose significant signal. I don't think that explanation holds water. If your hand was capable of blocking signals, cell phones would never have caught on.
 
1 - there are 2 GSM frequency bands used by AT&T for their network. 850 band and 1900 band. What is being used varies by location. Those living where 850 is more prevalent will be easier to duplicate the issue because the lower frequency band is more susceptible to issues such as these as opposed to the higher frequency band.

2 - Don't expect performance to be inversely proportional to the distance to the tower. All towers have a "null" area immediately below and surrounding them. So standing next to a tower and saying you get no/lower signal makes sense. This is compensated with overlap when the propagation study is done.
 
muteki99 said:
1 - there are 2 GSM frequency bands used by AT&T for their network. 850 band and 1900 band. What is being used varies by location. Those living where 850 is more prevalent will be easier to duplicate the issue because the lower frequency band is more susceptible to issues such as these as opposed to the higher frequency band.

2 - Don't expect performance to be inversely proportional to the distance to the tower. All towers have a "null" area immediately below and surrounding them. So standing next to a tower and saying you get no/lower signal makes sense. This is compensated with overlap when the propagation study is done.
Click to expand...

Fair enough. I did just read an article that stated towers have poor signal above and below them, so that could be an issue.

Your point in number 1 might give some credence to what I am speculating here, though. The towers near my house are probably older, while the others in town are probably newer, and maybe running on 1900 band.
 
muteki99 said:
1 - there are 2 GSM frequency bands used by AT&T for their network. 850 band and 1900 band. What is being used varies by location. Those living where 850 is more prevalent will be easier to duplicate the issue because the lower frequency band is more susceptible to issues such as these as opposed to the higher frequency band.

2 - Don't expect performance to be inversely proportional to the distance to the tower. All towers have a "null" area immediately below and surrounding them. So standing next to a tower and saying you get no/lower signal makes sense. This is compensated with overlap when the propagation study is done.
Click to expand...

Exactly!
 
Careful...a thread filled with facts and common sense has no place where emotional responses to everything run high :D

Is there anyway to verify if your in the 850/1900 band?

My tower was Edge only when I first got my 3G, about 3 months after they put in 3G so I'd assume it was 1900?

That would have been 3 years ago?
 
Long story short, my buddy got his iP4 yesterday and neither of us could recreate the loss of signal/dropped call problem after multiple attempts in his townhouse (5 bars the entire time).

At his office today (50+ miles away), he tells me that he had no problem recreating the issue several times and that he didn't have to grip the phone hard at all - just a light touch to the magic spot.

So I agree that it seems that those who think they don't have the problem are probably just not testing it on the right combination of signal strength, tower frequency, etc (whatever that combination is).

That's unfortunate, as my buddy was pretty excited yesterday thinking that he got a "good one".
 
muteki99 said:
1 - there are 2 GSM frequency bands used by AT&T for their network. 850 band and 1900 band. What is being used varies by location. Those living where 850 is more prevalent will be easier to duplicate the issue because the lower frequency band is more susceptible to issues such as these as opposed to the higher frequency band.

2 - Don't expect performance to be inversely proportional to the distance to the tower. All towers have a "null" area immediately below and surrounding them. So standing next to a tower and saying you get no/lower signal makes sense. This is compensated with overlap when the propagation study is done.
Click to expand...

exactly
 
muteki99 said:
1 - there are 2 GSM frequency bands used by AT&T for their network. 850 band and 1900 band. What is being used varies by location. Those living where 850 is more prevalent will be easier to duplicate the issue because the lower frequency band is more susceptible to issues such as these as opposed to the higher frequency band.
Click to expand...

This is nonsense!

It's a very basic scientific fact that HIGHER frequency signals are more easily disrupted, be that by distance or obstacles. That's why AT&T is rolling out 3G on 850MHz (like they just did in New York) to help improve their coverage.

I have experienced this issue on 900MHz, 1800MHz and 2100MHz here in the UK.

Frequency isn't the cause of this issue, nor is it AT&T.
 
Eric-PTEK said:
Careful...a thread filled with facts and common sense has no place where emotional responses to everything run high :D

Is there anyway to verify if your in the 850/1900 band?

My tower was Edge only when I first got my 3G, about 3 months after they put in 3G so I'd assume it was 1900?

That would have been 3 years ago?
Click to expand...

If the field test mode wasn't disabled in the iOS 4, determining which band you are on would be easy. I would suggest having a friend with a phone from a different manufacturer with a known test mode that works (on the same network, obviously) and try it out in your general vicinity.
 
Daveoc64 said:
This is nonsense!

It's a very basic scientific fact that HIGHER frequency signals are more easily disrupted, be that by distance or obstacles. That's why AT&T is rolling out 3G on 850MHz (like they just did in New York) to help improve their coverage.

I have experienced this issue on 900MHz, 1800MHz and 2100MHz here in the UK.

Frequency isn't the cause of this issue, nor is it AT&T.
Click to expand...

I am not implying that operating on one frequency will get rid of the issue completely, or that operating on another will cause the issue to occur 100% of the time. Nor am I implying that the issue is do to "distance" or "obstacles". It has to more to do with the close proximity of the separate antennas and the fact that your body can establish contact with both simultaneously.

You should be able to duplicate this across the board, but to what degree depends not only on operating frequency but environmental factors as well. This is all based around looking at the bars as well, which is a less than scientific approach, as their specific functionality is unknown.
 
Daveoc64 said:
This is nonsense!

It's a very basic scientific fact that HIGHER frequency signals are more easily disrupted, be that by distance or obstacles. That's why AT&T is rolling out 3G on 850MHz (like they just did in New York) to help improve their coverage.

I have experienced this issue on 900MHz, 1800MHz and 2100MHz here in the UK.

Frequency isn't the cause of this issue, nor is it AT&T.
Click to expand...

You might tone it down a bit. Unless you are an expert in this field, you shouldn't be speaking as if you are an expert.

Having said that, what most of us are debating is more about the phone and tower's ability to switch or adapt to problems in frequency, not so much the frequency itself, nor the ease with which they are disrupted.
 
I am in Manhattan and neither me nor any friends/colleagues are able to replicate the issue. I believe NYC is in the 850 band.
 
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