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Derek87

macrumors 6502a
Original poster
Jan 29, 2009
693
161
http://9to5mac.com/2014/05/15/att-a...one-6ios-8-integration-this-fall/#more-323334

so, i read this announcement today and realized that i continue to be puzzled by the following:

if the iPhone doesn't use LTE for voice, why does my reception for voice (number of bars or SNR level) change depending on whether LTE data is toggled on or off.

the different isn't small. at my office, its a 15db different (1-2 bars), and i get notably more reliable calling by leaving LTE off in the office lest i get one bar (-105 to -110 db) of reception in many parts of our office building.

what is going on that leads to my weaker voice reception when LTE is on?
 
It sounds like your phone is bouncing between two towers, one that supports LTE and one that doesn't. The phone is favoring the LTE signal due to the settings defined by your carrier, but the signal coming from the LTE tower is weaker. When you disable LTE your phone then grabs on to the stronger non-LTE signal.
 
It sounds like your phone is bouncing between two towers, one that supports LTE and one that doesn't. The phone is favoring the LTE signal due to the settings defined by your carrier, but the signal coming from the LTE tower is weaker. When you disable LTE your phone then grabs on to the stronger non-LTE signal.

i understand that entirely.

but perhaps, my question is not clear: all the articles i've read (including the one i cite) suggest that voice occurs, as of today on AT&T, only via 3G/4G. if that were the case, why does my data setting of LTE/4G affect voice signal strength?

(or is the phone actually indicating "data strength" rather than "voice strength"
 
Your voice reception shouldn't change based on whether LTE is toggled on or off. When a voice call comes in LTE automatically switches to "4G" no matter what.

Like for me inside my apartment I get 3-4 bars on LTE or 5 bars when I'm on 4G. So if I'm sitting here browsing the web on my iPhone with a 3 bar LTE signal, when a phone call comes in it switches to 5 bars and 4G. If I turn the LTE switch off then it's still just 5 bars 4G regardless on and off a phone call.

Might be a problem with reception in your area or just minor signal fluctuation. Or it could be a network issue. I'm on T-Mobile so I'm not sure whether AT&T handles voice/data differently while on calls.
 
i understand that entirely.

but perhaps, my question is not clear: all the articles i've read (including the one i cite) suggest that voice occurs, as of today on AT&T, only via 3G/4G. if that were the case, why does my data setting of LTE/4G affect voice signal strength?

(or is the phone actually indicating "data strength" rather than "voice strength"

No I get it, and I probably also misspoke. I doubt we're actually talking about two different towers here.

The LTE signal is using a different frequency than the 3G/4G (i.e. GSM) signal is, and those two frequencies will penetrate buildings differently. In your case I'm assuming the GSM signals are lower frequency, which can penetrate buildings more easily. This is why when you start using the GSM signal, you see your signal strength increase.

Like I said, your phone is trying to hold on to a weaker signal in order to maintain that LTE connection. It will continue to do that until you have a call. When you do I bet you will see the same behavior CEmajr describes.
 
thanks guys, i think i understand now. it also explains what my friend asked me recently: why did his phone show 4G for data whenever he was making a phone call and doing simultaneous data/voice.
 
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