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iPhone keeps switch from LTE to 4G (AT&T)

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willdude

macrumors regular
Original poster
Jul 16, 2010
238
184
I'm sitting at a friend's apartment right now where I've always been able to use the LTE network, and my phone consistently stayed connected to it. Since last night, though, my phone keeps switching to 4G and not switching back. When I toggled LTE off and on, it'll switch to LTE with about 3 bars, and I'll get a consistent 6 Mbps down. But after about minute, it'll switch to 4G with 4 bars and about 2 Mbps down. It won't switch back to LTE unless I toggle LTE, and then again it'll only stay connected for about a minute then switch back to 4G.

I've never seen this happen before here, and I suspect it has to do with updating to iOS 6.1 last week. It seems like there's a new feature where it'll prefer 4G over LTE if 4G has a stronger signal, despite the face that LTE would still have significantly higher speeds. Resetting network settings has not helped. Has anyone else seen this?
 
W

willdude

macrumors regular
Original poster
Jul 16, 2010
238
184
AutoUnion39 said:
It is seeking the stronger 3G signal over the weak LTE signal. Normal.
Click to expand...

I suppose this is theoretically possible, except that:

a) In the 4+ months of having this phone, it's never had a problem maintaining an LTE connection in this exact spot. (Like, literally, the couch I'm sitting on.) It was fine up until last night, then started switch to 4G.

b) The signal strength is, like, 3 bars versus 4. And even with the lower strength, LTE still gets 3x the download speed.

Maybe it's just some problem with AT&T that'll work itself out.

Random question which might be related: When you're on LTE and receive a call, the phone switches to 4G. How does the phone know to do this? I'm wondering if it's erroneously getting some sort of signal to switch to 4G in anticipation of a call which isn't actually coming.
 
2

2298754

Cancelled
Jun 21, 2010
4,890
941
willdude said:
I suppose this is theoretically possible, except that:

a) In the 4+ months of having this phone, it's never had a problem maintaining an LTE connection in this exact spot. (Like, literally, the couch I'm sitting on.) It was fine up until last night, then started switch to 4G.

b) The signal strength is, like, 3 bars versus 4. And even with the lower strength, LTE still gets 3x the download speed.

Maybe it's just some problem with AT&T that'll work itself out.
Click to expand...

What's your location? Maybe something is off due to the recent storms (only possible if you're in the Northeast)
 
A

apple111115

macrumors regular
May 21, 2011
112
6
YES, IT ISN'T JUST ME! LOL. I am having an issue just like this too. I am also on AT&T with an iPhone 5.
 
W

willdude

macrumors regular
Original poster
Jul 16, 2010
238
184
AutoUnion39 said:
What's your location? Maybe something is off due to the recent storms (only possible if you're in the Northeast)
Click to expand...

Baltimore. No snow down here (but still cold). That's a pretty reasonable explanation, though. AT&T might be artificially kicking people down to 4G to prevent an overloaded LTE network in the Northeast, even in places on the fringes of the affected area.

apple111115 said:
YES, IT ISN'T JUST ME! LOL. I am having an issue just like this too. I am also on AT&T with an iPhone 5.
Click to expand...

What's your location? How long have you been seeing this? Did it correspond to increased LTE usage (video streaming) like mine did?

Edit: I'm wiling to bet this is the explanation.

AT&T support emergency notifications on its older “4G: HSPA+ network, but can’t send the notices to users on its 4G LTE network. So while iPhone 5 users on Verizon and Sprint jumped because of the sirens coming from their phones, AT&T iPhone 5 users heard nothing.
Click to expand...


AT&T could be kicking people off LTE to make sure they get emergency notifications.
 
Y

yeah

macrumors 6502a
Jul 12, 2011
978
291
willdude said:
I suppose this is theoretically possible, except that:

a) In the 4+ months of having this phone, it's never had a problem maintaining an LTE connection in this exact spot. (Like, literally, the couch I'm sitting on.) It was fine up until last night, then started switch to 4G.

b) The signal strength is, like, 3 bars versus 4. And even with the lower strength, LTE still gets 3x the download speed.

Maybe it's just some problem with AT&T that'll work itself out.

Random question which might be related: When you're on LTE and receive a call, the phone switches to 4G. How does the phone know to do this? I'm wondering if it's erroneously getting some sort of signal to switch to 4G in anticipation of a call which isn't actually coming.
Click to expand...

Since LTE can't handle Voice (until VoLTE is launched), the phone detects the phone signal to answer the call and shuts off the LTE antenna until the call is ended. All in a blink of an eye ;) (get my pun?) :p
 
Goaliegeek

Goaliegeek

macrumors 6502a
Apr 13, 2009
568
209
Colorado
I've been having this issue as well, though worse. Found out it's an ATT/ATT iPhone issue. With me, I may get some LTE signal, then it will go away, along with all my cellular data service. My iPhone wont connect to any network (LTE/E/4G) unless I do an airplane mode toggle. Sometimes, it will go from LTE to 4G, but nothing happens. I try and load something and it just sits there. So I have to toggle. Happens to my friends iPhone as well. But my girlfriend's Verizon iPhone doesn't have any issues. She has full LTE everywhere. I'm lucky if I get any coverage (Denver metro area).
 
I

ineel

macrumors regular
Jul 8, 2010
211
11
At&t

This is how AT&T designed their network. Precisely they used their 700Mhz spectrum to deploy LTE. 700Mhz does not get attenuated as easily as higher frequency bands and has better building penetration. AT&T knowing this has stated that they are not upgrading every tower in each locality to LTE. instead they are upgrading towers to LTE only on some towers and skipping others. Because not everyone has LTE now, it doesn't make sense to make their LTE network so dense as their 3G network. Thus if a HSPA+ enabled tower is closer than another LTE tower further away your iPhone will prefer that better signal. As more and more AT&T customers uptake LTE phone AT&T will eventually upgrade all of their towers to LTE as needed. You can tell if a tower is LTE enabled by simply toggling back and forth between lte and 4g. If the signal bars changes for each you'll know you're standing next to an un upgraded tower.
 
A

apple111115

macrumors regular
May 21, 2011
112
6
That makes a lot of sense! Thanks! :)

It seems to me, though, that I used to get LTE in this area, but not anymore. Is the "switching technology" new/just implemented?
 
W

willdude

macrumors regular
Original poster
Jul 16, 2010
238
184
This doesn't really explain, though, why I've always gotten LTE signal here before, but all of a sudden it started preferring 4G. Unless they just put up a 4G-only tower nearby on Friday night.

I can say, though, that it's location/tower specific. Last night traveling around the city, I got LTE everywhere else except where I'm having the problem. And again, I just don't understand why it would prefer 4G when it's only 1 bar stronger and 1/3 the speed.
 
oplix

oplix

Suspended
Jun 29, 2008
1,460
487
New York, NY
I had a thread on this issue 1 week after release. It's really difficult to pinpoint the culprit since it can be software and/or hardware related.
 
I

inet27

macrumors newbie
Jul 5, 2007
8
4
Pride of Colorado
Goaliegeek said:
I've been having this issue as well, though worse. Found out it's an ATT/ATT iPhone issue. With me, I may get some LTE signal, then it will go away, along with all my cellular data service. My iPhone wont connect to any network (LTE/E/4G) unless I do an airplane mode toggle. Sometimes, it will go from LTE to 4G, but nothing happens. I try and load something and it just sits there. So I have to toggle. Happens to my friends iPhone as well. But my girlfriend's Verizon iPhone doesn't have any issues. She has full LTE everywhere. I'm lucky if I get any coverage (Denver metro area).
Click to expand...

I'm having the same issue in Denver metro area. I called AT&T and they pointed me to Apple because it's a "device" issue. I'm going to the Apple store tomorrow. It's all a numbers game the more people that complain the more attention it will get.

But here we go with the finger pointing game. I have a finger I'd like to show both of them at this point.
 
V

v.pic

macrumors newbie
Mar 2, 2012
12
0
Killadelphia
iPhone 5 on AT&T in Philadelphia, here.

I had the same problem for awhile. After I finally called my carrier & had them reset the tower's connection to the SIM, things stabilized enough for me to realize what actually was kicking me
off LTE time & time again:

Passbook. Passbook, when fully enabled, checks your general location everytime you wake the iPhone. By realizing the correlation between the boot & the location arrow, I went to see which location service was consistently checking; & followed with reverting to 4G.

It was Passbook, and I believe I know why. Rather than have GPS satellites search everytime you light up your phone, Passbook (I believe) uses the nearest cell tower.
Well; the nearest cell tower to me is not LTE. It's 4G. However I do have LTE service.
So I believe that everytime my phone looked to the nearest tower for location — I lost my 2-3 bar LTE connection, and just didnt get it back.

As of now: for the first time since I've had my iPhone 5, I've been on solid LTE for almost an hour.
Will any cell-tower location search cause the same behavior? Possibly. But at least now it won't occur everytime I go to use the phone.


In other words; turn off Passbook location services, reset network settings, & have your carrier reset the network's connection to your phone.
That should limit disconnection enough until those of us in work-in-progress LTE tower zones get better service.
 
Last edited:
C

Chuck Militti

macrumors newbie
May 28, 2013
1
0
v.pic said:
iPhone 5 on AT&T in Philadelphia, here.

I had the same problem for awhile. After I finally called my carrier & had them reset the tower's connection to the SIM, things stabilized enough for me to realize what actually was kicking me
off LTE time & time again:

Passbook. Passbook, when fully enabled, checks your general location everytime you wake the iPhone. By realizing the correlation between the boot & the location arrow, I went to see which location service was consistently checking; & followed with reverting to 4G.

It was Passbook, and I believe I know why. Rather than have GPS satellites search everytime you light up your phone, Passbook (I believe) uses the nearest cell tower.
Well; the nearest cell tower to me is not LTE. It's 4G. However I do have LTE service.
So I believe that everytime my phone looked to the nearest tower for location — I lost my 2-3 bar LTE connection, and just didnt get it back.

As of now: for the first time since I've had my iPhone 5, I've been on solid LTE for almost an hour.
Will any cell-tower location search cause the same behavior? Possibly. But at least now it won't occur everytime I go to use the phone.


In other words; turn off Passbook location services, reset network settings, & have your carrier reset the network's connection to your phone.
That should limit disconnection enough until those of us in work-in-progress LTE tower zones get better service.
Click to expand...

I just turned off Passbook location settings and now have my LTE signal back full time!
 
SpaceKitty

SpaceKitty

macrumors 68040
Nov 9, 2008
3,204
1
Fort Collins Colorado
I don't have an iPhone 5 but an iPad Mini. I had to turn off LTE because we just don't have it in my area in Denver yet. The few times it did switch to LTE, it was slower then edge speeds and unusable.

AT&T LTE still isn't built out yet everywhere.
 
ilustrisimo08

ilustrisimo08

macrumors newbie
Nov 26, 2013
1
0
Virginia
I really thought I was the only one dealing with this issue.

I'm coming from the Bay Area in California too. I used to work and live in Berkeley where I had that issue quite a bit. I thought that it was just the signal where I work because there are areas of Berkeley where I do not get reception at all (University ave). But I just started working in Palo Alto and live in Fremont, and yet I am still dealing with these problems in those areas too!
 
hancox

hancox

macrumors member
Dec 22, 2011
88
67
Goaliegeek said:
I've been having this issue as well, though worse. Found out it's an ATT/ATT iPhone issue. With me, I may get some LTE signal, then it will go away, along with all my cellular data service. My iPhone wont connect to any network (LTE/E/4G) unless I do an airplane mode toggle. Sometimes, it will go from LTE to 4G, but nothing happens. I try and load something and it just sits there. So I have to toggle. Happens to my friends iPhone as well. But my girlfriend's Verizon iPhone doesn't have any issues. She has full LTE everywhere. I'm lucky if I get any coverage (Denver metro area).
Click to expand...

Same issue with me - seems to happen more since 7.0.3 or 7.0.4 though.
 
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