Develop Bugs

[Q] Why can't we use data during a call?

So I was downloading AA V7 from my phone. Since I was at work. I started about 6 20 pm. On a 100% battery. Around 8 20 pm with a 28 % battey I was at 96% when I got a phone call and canceled my download. Why o why. Damn u sprint. Does any one know if 4g will stay connected while your in a call?
Sent from my fake Nexus S 4G using XDA Premium App

notsosmrtgeek said:
So I was downloading AA V7 from my phone. Since I was at work. I started about 6 20 pm. On a 100% battery. Around 8 20 pm with a 28 % battey I was at 96% when I got a phone call and canceled my download. Why o why. Damn u sprint. Does any one know if 4g will stay connected while your in a call?
Sent from my fake Nexus S 4G using XDA Premium App
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Click to collapse
Cdma will not allow data and calling its a network thing...a no no but 4g works I tested it before and it works no problem
Sent from my SPH-D700 using XDA App

Thanks. I don't get 4g at my work but in my town there is. but I will just dl it later. Damn sprint
Sent from my fake Nexus S 4G using XDA Premium App

I feel your pain
Sent from my SPH-D700 using XDA Premium App

You can use wifi while on a call

rulyskull said:
Cdma will not allow data and calling its a network thing...a no no but 4g works I tested it before and it works no problem
Sent from my SPH-D700 using XDA App
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I know, why doesn't Sprint advertise that fact? I've found myself surprised when I get a call while doing interweb things and everything continues as is. By the way, I think HBO GO thinks 4g=wifi.

And that's why GSM is so much better...
SIM cards > ESN
Data and voice simultaneously? Yes please.
IIRC it's frequencies penetrate buildings better as well.

I normally have wifi on at home because I am in between. Areas at my apt so I knew about the wifi but there is always a negative fml. But at home time for some v7. I have about 30 pages to catch up on heheheh.
Sent from my fake Nexus S 4G using XDA Premium App

I was able to take a call and use data..I have Sprint. I was in a 4G area. Voice and data shouldnt be a problem at the same time. I had an Adobe connect going. Never lost connection and I was using wired tether..I am rooted. But no issues
Sent from my Swagurious Evo...

I have googled something while on a phone call without 4G or wifi. Heavy traffic stops or crawls so much you may think it doesn't work or timeouts.

Kal*El said:
I was able to take a call and use data..I have Sprint. I was in a 4G area. Voice and data shouldnt be a problem at the same time. I had an Adobe connect going. Never lost connection and I was using wired tether..I am rooted. But no issues
Sent from my Swagurious Evo...
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Okay everyone, let me teach you a little something. AT&T and T-Mobile both allow you to use data while on a call, why is that? It is actually because, back in the days before data, AT&T used ONLY GSM radio frequencies. These were perfect for phone calls and texting, but once data connections were required, their network couldn't handle it.
However, Sprint and Verizon were fine, because they used CDMA, a network that allows them to handle voice and data on the same frequency.
GSM providers were sad, so to fix it, they added a CDMA frequency to their arsenal. This means, they use two frequencies at the same time a GSM frequency to handle calls and text, and a CDMA frequency to handle data. So while you are on a call, the CDMA frequency is still free, hence the talk and web simultaneously.
Sprint and Verizon, however use CDMA for everything, so when you make a phone call, the network is being used. So data can't also get through. But 4G is yet another frequency so that can be used at the same time as a phone call.
Does this make sense?
Also, while GSM can penetrate buildings better, it is also much less reliable. It's large wavelengths allow it to travel through walls better, but also cause the dredded dropped calls that AT&T experience so much. I'll take CDMA over GSM everyday of the week. Besides, other then the rare occasion in which we are downloading (though we should never download something that big over 3G) we don't NEED talk and data at the same time.

The Root said:
I know, why doesn't Sprint advertise that fact? I've found myself surprised when I get a call while doing interweb things and everything continues as is. By the way, I think HBO GO thinks 4g=wifi.
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Why would sprint advertise a flaw. That's why att advertises that they can talk and surf with the iphone duh

i know it doesnt work and it takes forever. but i am a flashaholic and damn it sucks when i go to work and the rom i have been waiting for gets released

There are a bunch of errors here.
CDMA can do Voice and data at the same time. Verison did not want that, and as the largest CDMA company, every one stopped developing new and better protocols and by default standardized on the Verizon way.
But not all Dev stopped. Outside North America there are several CDMA carriers that use EVDV? and other protocols that allow simultaneous Voice data connections on their frequencies. I believe Russia does on their 450MHz system. In fact these protocols are built in to any newer phone and all new tower equipment, but has not been implemented. Some have suggested when Sprint finishes their soft radio upgrade, they may offer it on a new phone.
Censura_Umbra had much good info, but it is not NECESSARY, from a tech point of view to have two different frequencies to do voice and data. It has been suggested that ATT wanted TWO separate systems for voice and data, as that is how big telcos are. I find this accurate.
One should also note that there are SIM CDMA phones. SIM is a separate tech entirely. North American Vendors do not use SIM cards to protect there handset hardware revenue streams. It is also why they lobbied so hard to try to get ESN modification illegal.
Final point. There are plenty who complain about frequency penetration.
1) While lower frequencies do penetrate things better, and thus may have more cancer risk
2) They also take more power to create. Thus reducing phone life.
3) Frequency attenuation do to penetration is predictable. With modern protocols, data rates can be unaffected. These things are not being implemented do to the FAT revenue streamed on handsets.

I'm not sure what everyone is talking about, I use 3G a lot while on calls.

Censura_Umbra said:
Okay everyone, let me teach you a little something. AT&T and T-Mobile both allow you to use data while on a call, why is that? It is actually because, back in the days before data, AT&T used ONLY GSM radio frequencies. These were perfect for phone calls and texting, but once data connections were required, their network couldn't handle it.
However, Sprint and Verizon were fine, because they used CDMA, a network that allows them to handle voice and data on the same frequency.
GSM providers were sad, so to fix it, they added a CDMA frequency to their arsenal. This means, they use two frequencies at the same time a GSM frequency to handle calls and text, and a CDMA frequency to handle data. So while you are on a call, the CDMA frequency is still free, hence the talk and web simultaneously.
Sprint and Verizon, however use CDMA for everything, so when you make a phone call, the network is being used. So data can't also get through. But 4G is yet another frequency so that can be used at the same time as a phone call.
Does this make sense?
Also, while GSM can penetrate buildings better, it is also much less reliable. It's large wavelengths allow it to travel through walls better, but also cause the dredded dropped calls that AT&T experience so much. I'll take CDMA over GSM everyday of the week. Besides, other then the rare occasion in which we are downloading (though we should never download something that big over 3G) we don't NEED talk and data at the same time.
Click to expand...
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I'm very well versed in gsm cdma and tdma networks....voice and data at the same time will depend on a personal preference. I enjoyed using it bc I do meetings on the go. Sprint's network will allow that.
Ppl are getting confused with 3G...bc they assume since ATT has this that all carriers should have it..4G allows this.....
Sent from my Swagurious Evo...

[Q] The Verizon Nexus and VoLTE?

Verizon has a Voice over LTE system coming out in the next year(according to them). That would allow the LTE radio to not just be used for sweet delicious data, but be used for voice(minutes?) too. Is this something that the current Galaxy Nexus will be capable of in the future via firmware update? This would solve some of the battery draining problems related to using a LTE phone. It would suck burro pene having a relatively new LTE phone and not be able to use Verizon's forthcoming VoLTE platform in a few months, if there is a huge benefit from it.

Pacifik said:
Verizon has a Voice over LTE system coming out in the next year(according to them). That would allow the LTE radio to not just be used for sweet delicious data, but be used for voice(minutes?) too. Is this something that the current Galaxy Nexus will be capable of in the future via firmware update? This would solve some of the battery draining problems related to using a LTE phone. It would suck burro pene having a relatively new LTE phone and not be able to use Verizon's forthcoming VoLTE platform in a few months, if there is a huge benefit from it.
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I don't see how using LTE for voice AND data will make battery life any better.

Chirality said:
I don't see how using LTE for voice AND data will make battery life any better.
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turn off the CDMA radio completely?

crazy talk said:
turn off the CDMA radio completely?
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The LTE radio is the one that burns the battery, not the CDMA radio. So once you start doing voice and data both over LTE its gonna rape the battery lol.

Currently you get a call it's handed off to the CDMA antenna. When on LTE both the CDMA for voice and LTE for data are on. Whereas with VoLTE while on LTE there is no hand off, therefore no secondary voice antenna needs to be on as the LTE handles it.

Pacifik said:
Currently you get a call it's handed off to the CDMA antenna. When on LTE both the CDMA for voice and LTE for data are on. Whereas with VoLTE while on LTE there is no hand off, therefore no secondary voice antenna needs to be on as the LTE handles it.
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That's not true at all. When the CDMA radio is on for voice communication it turns *off* the LTE radio. We know this because voice and data at the same time are not possible on most LTE phones.
If you used the LTE radio for voice communication, as well as data, it would *completely* destroy your battery life.

hotleadsingerguy said:
That's not true at all. When the CDMA radio is on for voice communication it turns *off* the LTE radio. We know this because voice and data at the same time are not possible on most LTE phones.
If you used the LTE radio for voice communication, as well as data, it would *completely* destroy your battery life.
Click to expand...
Click to collapse
On Verizon LTE phones you can 100% definitely use 4g data while on 3g voice, most can't do 3g simultaneous voice and data. While LTE ants use more power, powering up a second antenna while already using the LTE will hurt even more. There will also be usually be an increase in call quality on an LTE call. All of this is under the assumption you actually plan on using the 4G network.

Important question that needs an answer
I too am considering getting the new Galaxy Nexus on VZ. The battery issue I find secondary to my main concern, but it should be obvious that using only one radio (LTE) will have power saving benefits vs two radios. If just using voice, it may be a net loss of battery life. I guess we'll see how LTE stacks up to CDMA power consumption.
But here is the important question: will the SGN be upgradeable to support VoLTE (Voice over LTE) and the accompanying high-definition audio codec AMR-WB. You see, your horrible-sounding cell calls will transform to sounding better than a land line (assuming, of course, a compatible phone on the other end). It is even conceivable one could call VoIP landlines that support this codec and get good audio quality.
So you see, it is really all about the audio quality. Battery life is secondary, and may go up or down depending on your useage of voice only or voice and data.

[email protected] said:
I too am considering getting the new Galaxy Nexus on VZ. The battery issue I find secondary to my main concern, but it should be obvious that using only one radio (LTE) will have power saving benefits vs two radios. If just using voice, it may be a net loss of battery life. I guess we'll see how LTE stacks up to CDMA power consumption.
But here is the important question: will the SGN be upgradeable to support VoLTE (Voice over LTE) and the accompanying high-definition audio codec AMR-WB. You see, your horrible-sounding cell calls will transform to sounding better than a land line (assuming, of course, a compatible phone on the other end). It is even conceivable one could call VoIP landlines that support this codec and get good audio quality.
So you see, it is really all about the audio quality. Battery life is secondary, and may go up or down depending on your useage of voice only or voice and data.
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If the wideband voice codec is implemented in hardware, then sure it can be a software upgrade. Otherwise its up to the CPU to do all the processing which isn't ideal. Still could be done though, just not in an optimal fashion.

the downsides outweigh the very small benefits. yeah, just using a lte antenna and turning off cdma will net you a small gain, but having lte on 24/7 will burn through the battery quickly and using it for voice just to gain a little clarity will still burn through the battery, just now you're using more power compared to cdma voice. nice try though.

pukemon said:
the downsides outweigh the very small benefits. yeah,
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Then get a CDMA phone and keep having your phone conversations in low-def. Each to their own.
Personally, I absolutely despise cellphone audio quality (what? What did you say?) and will gladly burn a few extra milliamps, if indeed there is much of a penalty, for the few minutes I am actually talking on the phone.
---------- Post added at 04:41 PM ---------- Previous post was at 04:37 PM ----------
aadvanced1 said:
If the wideband voice codec is implemented in hardware, then sure it can be a software upgrade. Otherwise its up to the CPU to do all the processing which isn't ideal. Still could be done though, just not in an optimal fashion.
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My understanding is that the voice codec must be in the modem firmware. Supposedly, from what I have read on the internet, the SGN uses the same SGS Thomson modem as the Samsung Galaxy II, which is capable of VoLTE. Again, reading on the internet, VZ has specifically asked Samsung (this was noted in the FCC filing) to ship it without VoLTE, presumably for better compatibility with their network today.
So, the million dollar question is: Is this just a firmware upgrade to enable when VoLTE goes live on VZ? Pretty sure modem firmware is different from Android OS. Not sure if it is upgradeable after the fact. Is this what is commonly refered to as "baseband firmware"?
Does anybody know more about the guts of these phones?

pass. i'll stick to gsm for a while longer. much longer. much better on the battery, call quality is satisfactory and i can travel with it. when lte power consumption is comparable to that of current hspa/cdma radios i might consider switching. until then i'm going to try and make my nexus last a couple years.

[email protected] said:
Then get a CDMA phone and keep having your phone conversations in low-def. Each to their own.
Personally, I absolutely despise cellphone audio quality (what? What did you say?) and will gladly burn a few extra milliamps, if indeed there is much of a penalty, for the few minutes I am actually talking on the phone.
Click to expand...
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Totally agreed. Going from a cell conversation to a Skype to Skype call makes you realize how undescribably bad cell voice quality is.

here's the million dollar question: With voLTE, can I simultaneously use voice and data over 4g?

Pacifik said:
Verizon has a Voice over LTE system coming out in the next year(according to them). That would allow the LTE radio to not just be used for sweet delicious data, but be used for voice(minutes?) too. Is this something that the current Galaxy Nexus will be capable of in the future via firmware update? This would solve some of the battery draining problems related to using a LTE phone. It would suck burro pene having a relatively new LTE phone and not be able to use Verizon's forthcoming VoLTE platform in a few months, if there is a huge benefit from it.
Click to expand...
Click to collapse
It's a really good question. If I had to bet, I'd say yes. I'd bet they've got Samsung putting the codec into the modem firmware already. I'd bet their 4G device testing already includes VoLTE IMS along with one or two production test markets for VZW field testing. I think the odds are good. That said, they don't exactly advertise on the box:
"Supports VoLTE so in about 9 months your battery life won't completely suck and maybe you'll get HD audio if you're seriously lucky."
Samzebian said:
here's the million dollar question: With voLTE, can I simultaneously use voice and data over 4g?
Click to expand...
Click to collapse
Yes. You should be able to do this even without VoLTE using 3G voice and 4G data. Different radios.

Samzebian said:
here's the million dollar question: With voLTE, can I simultaneously use voice and data over 4g?
Click to expand...
Click to collapse
Voice over LTE treats the call as data, it's the same thing as a voip call essentially.

Cdma data and phone

I don't know when this happened, but on Verizon you can be on the phone and use data at the same time. At&t has nothing on Verizon now.
Sent from my Galaxy Nexus using XDA App

It's 4G voice goes over 3G and data over 4G

EKnofsky said:
It's 4G voice goes over 3G and data over 4G
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How long have we had these capabilities? This opens a few more doors for me.
Sent from my Galaxy Nexus using XDA App

You can do this on the Thunderbolt in 3G only areas too. I think because HTC used 2 radios or somesuch. The Nexus can not do Data/voice in 3G only areas.

piperat said:
I don't know when this happened, but on Verizon you can be on the phone and use data at the same time. At&t has nothing on Verizon now.
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4G gives data, 3G does voice. You can do this and its been a feature since the start.
kenyu73 said:
You can do this on the Thunderbolt in 3G only areas too. I think because HTC used 2 radios or somesuch. The Nexus can not do Data/voice in 3G only areas.
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True. The Thunderbolt has a special radio that does simultaneous voice/data on 3G.

piperat said:
I don't know when this happened, but on Verizon you can be on the phone and use data at the same time. At&t has nothing on Verizon now.
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Verizon 4G devices still have to use 3G for voice at least until VoLTE is switched on next year. Having two radios always on is part of the reason why the Verizon version has such horrible battery life.

ianwood said:
Verizon 4G devices still have to use 3G for voice at least until VoLTE is switched on next year. Having two radios always on is part of the reason why the Verizon version has such horrible battery life.
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I hope when 3G is turned off that simultaneous voice/data isnt lost!!
I think there is alot more to it then having two radios on. Isn't 1x a radio? I've never followed radio technology so I really dont know all the details, but I'm pretty sure the 4G radio itself can do voice/data as well as support 3G and 1x as well. I dont think every 4G handset contains both 3G and 4G chips. I may be wrong, but it seems a bit of wasted space!

kenyu73 said:
I hope when 3G is turned off that simultaneous voice/data isnt lost!!
I think there is alot more to it then having two radios on. Isn't 1x a radio? I've never followed radio technology so I really dont know all the details, but I'm pretty sure the 4G radio itself can do voice/data as well as support 3G and 1x as well. I dont think every 4G handset contains both 3G and 4G chips. I may be wrong, but it seems a bit of wasted space!
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Click to collapse
3g for vzw isnt getting shut off for sometime (i think like 2014). its verizons major voice backbone.
1x uses the same chip as 3g and every LTE handset has 2 radios.

kenyu73 said:
I hope when 3G is turned off that simultaneous voice/data isnt lost!!
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You won't lose it. Voice is treated like just another data type in LTE which means VoLTE inherently supports concurrent voice/data.
Zepius said:
3g for vzw isnt getting shut off for sometime (i think like 2014). its verizons major voice backbone.
1x uses the same chip as 3g and every LTE handset has 2 radios.
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It's about having radios on at the same time. LTE/UMTS/GSM does not run 2 radios simultaneously and supports seamless in-session handovers including the signaling of mobile terminated calls (LTE release 9). It is almost effectively the same as concurrent voice and data in UMTS/GSM. In LTE/CDMA you run both radios concurrently unless you turn LTE off.

Thread closed

I haven't noticed until know that the SGN from Verizon shuts off 3g/lte while making calls.
Does this have something to do with ATTs contract with Google and Samsung.
I will leave this thread open as hope that we can resolve this issue. Please post your experiences. If your are not having issues with your SGN from Verizon please post. Thank you
Oh yeah wtf? Right?

Its a limitation of cdma.
Sent from my Xoom using xda premium

OK but why did Verizon tell that me it does do calls and internet at the same time. Two customer reps told me this and one told me its in the manual. I'm going through the manual now

It's the network. Not some under the table contracted agreement.

It should be able to do voice and data anytime you have an LTE signal. On 3g you cannot though. Its a limitation of cdma.

Yeah Verizon has good towers here in California. Sh..ty service and BS like made me spill my coffee

Fine could we at least mod that out? I mean that's a load a crap

No.
Only LTE can coexist with calls.

Well what about a lte only switch if that was compiled than it would help right?

robitron929 said:
Well what about a lte only switch if that was compiled than it would help right?
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No. An LTE only switch would kill the cdma radio which is where the voice is routed on the Nexus.
Sent from my Galaxy Nexus using Tapatalk

robitron929 said:
Does this have something to do with ATTs contract with Google and Samsung?
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Click to collapse
*blink blink* TRWTF is the above question.
As stated, this is a limitation of CDMA, or at least Verizon's current implementation of CDMA. Every 3G phone exhibits this behavior, as well as LTE phones when out of range of an LTE signal.

copkay said:
*blink blink* TRWTF is the above question.
As stated, this is a limitation of CDMA, or at least Verizon's current implementation of CDMA. Every 3G phone exhibits this behavior, as well as LTE phones when out of range of an LTE signal.
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Click to collapse
There is one exception to the rule. VZW has updated their CDMA towers to allow SVDO which is voice and data over 3G, however the phone has to have a compatible chip set for it to work. The HTC thunderbolt is the only phone I know of that does SVDO when there is no LTE signal

theherodrownd said:
There is one exception to the rule. VZW has updated their CDMA towers to allow SVDO which is voice and data over 3G, however the phone has to have a compatible chip set for it to work. The HTC thunderbolt is the only phone I know of that does SVDO when there is no LTE signal
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Yeah, that's what's described at the "current implementation" link. As far as I was aware, SVDO hasn't been rolled out yet. Has Verizon already "flipped the switch" on SVDO?

copkay said:
Yeah, that's what's described at the "current implementation" link. As far as I was aware, SVDO hasn't been rolled out yet. Has Verizon already "flipped the switch" on SVDO?
Click to expand...
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SVDO was ready at launch of the TBolt. There was no press release when it launched tho. I don't think SVDO is going to catch on with VoLTE coming and the power hungry chips is just not q recipe for success

theherodrownd said:
SVDO was ready at launch of the TBolt. There was no press release when it launched tho. I don't think SVDO is going to catch on with VoLTE coming and the power hungry chips is just not q recipe for success
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Ah interesting, yeah, I didn't know that. They definitely didn't bother making a big deal out of it. Well, good to know, anyway.

Wow no option at this point

robitron929 said:
Wow no option at this point
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Welcome to CDMA. You can't do simultaneous talk and data over 3G. The only way you can do voice+data is if you're talking on 3G and doing data over LTE. If LTE drops while you're in a call, you have no data.

robitron929 said:
Wow no option at this point
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What are you even talking about? You have the entire technical reason behind your question, and you've been presented with the options (use LTE/WiFi). Alternatively, you can cancel your contract and move to AT&T -- have fun with that.

Well than i m guessing it would be a long shot to implement SVDO into a modded radios package
. Or maybe the hardware's incapable regardless

robitron929 said:
Well than i m guessing it would be a long shot to implement SVDO into a modded radios package
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Dude. It's a hardware limitation. It's like asking if you can download more RAM.

Simultaneous voice + data on Verizon?

I read there are some issues with the Galaxy S6 and some newer phones on Verizon being unable to do native simultaneous voice + data. I think because of a limit of the # of radios and/or antennas. What can we expect with the 5X on VZW? Thank you!

All new phones can do simultaneous voice and data only with VoLTE or while connected to WiFi. When connected to LTE (and no VoLTE) or 3G data they will drop to CDMA 1X if a call comes in. This is because they only have one antenna pathway and one radio. If they had a separate radio for LTE (like done older phones) it would drain battery almost twice as fast since mobile connection is one of your larger battery users.
Sent from my Nexus 6 using Tapatalk

_Dennis_ said:
All new phones can do simultaneous voice and data only with VoLTE or while connected to WiFi. When connected to LTE (and no VoLTE) or 3G data they will drop to CDMA 1X if a call comes in. This is because they only have one antenna pathway and one radio. If they had a separate radio for LTE (like done older phones) it would drain battery almost twice as fast since mobile connection is one of your larger battery users.
Sent from my Nexus 6 using Tapatalk
Click to expand...
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Ugh, what I feared. How do people do Nav and have phone calls at the same time? Is this going to work with VZW VoLTE on day one? May have made sense to design with two radios and two antennas and only activate the second one when necessary?

hytekjosh said:
Ugh, what I feared. How do people do Nav and have phone calls at the same time? Is this going to work with VZW VoLTE on day one? May have made sense to design with two radios and two antennas and only activate the second one when necessary?
Click to expand...
Click to collapse
Any time LTE is on the second would have to be on, or it wouldn't be able to seamlessly take the call, so that wouldn't have worked.
If your call isn't very long navigation would still work fine, it caches a bit in case of signal drop. The other option would be to download the route ahead of time, Google can do it now I think.
I have a feeling it should have VoLTE though, which would give you voice and data.
http://www.droid-life.com/2015/03/1...e-and-data-now-works-on-nexus-6-with-verizon/
Sent from my Nexus 6 using Tapatalk

_Dennis_ said:
Any time LTE is on the second would have to be on, or it wouldn't be able to seamlessly take the call, so that wouldn't have worked.
If your call isn't very long navigation would still work fine, it caches a bit in case of signal drop. The other option would be to download the route ahead of time, Google can do it now I think.
I have a feeling it should have VoLTE though, which would give you voice and data.
http://www.droid-life.com/2015/03/1...e-and-data-now-works-on-nexus-6-with-verizon/
Sent from my Nexus 6 using Tapatalk
Click to expand...
Click to collapse
Will the same limitations be on each carrier (ie. if I switch to AT&T I still need to use VoLTE for simultaneous voice + data)? Thank you!!

hytekjosh said:
Will the same limitations be on each carrier (ie. if I switch to AT&T I still need to use VoLTE for simultaneous voice + data)? Thank you!!
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Click to collapse
Nope, the way GSM and CDMA works are different. Say you don't have VoLTE and are on an LTE connection. The tower also has a spot for you on HSPDA and GSM if on Tmo or AT&T, or on CDMA if on Sprint or Verizon. If you get a call you fallback to HSPDA or GSM. A similar thing happens on CDMA. The difference is CDMA can't do voice and data on the same connection, GSM and HSPDA can do both.
Sent from my Nexus 6 using Tapatalk

_Dennis_ said:
Nope, the way GSM and CDMA works are different. Say you don't have VoLTE and are on an LTE connection. The tower also has a spot for you on HSPDA and GSM if on Tmo or AT&T, or on CDMA if on Sprint or Verizon. If you get a call you fallback to HSPDA or GSM. A similar thing happens on CDMA. The difference is CDMA can't do voice and data on the same connection, GSM and HSPDA can do both.
Sent from my Nexus 6 using Tapatalk
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Click to collapse
Really wish phones included a Ev radio so this would not be an issue. I wonder if the voice quality/codec on AT&T has improved over the years? Last I used them their voice quality was far inferior to VZW. May be time to consider a carrier switch.

I've not had problems with voice quality, the few times I call on AT&T. They weren't as good as Sprint (their new network has simply amazing voice quality, and data was OK lol).
Mostly I use Google voice via hangouts to make calls, so the network data is more important then voice quality.
Sent from my Nexus 6 using Tapatalk

_Dennis_ said:
All new phones can do simultaneous voice and data only with VoLTE or while connected to WiFi. When connected to LTE (and no VoLTE) or 3G data they will drop to CDMA 1X if a call comes in. This is because they only have one antenna pathway and one radio. If they had a separate radio for LTE (like done older phones) it would drain battery almost twice as fast since mobile connection is one of your larger battery users.
Sent from my Nexus 6 using Tapatalk
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How new? My S4 gets simultaneous voice/data on lte, but not on 3g. Are you sure you're right about this?

Well, the S4 is not a new phone. And yes I'm certain without advanced calling (or VoLTE) you will not have voice and data on LTE at the same time.
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Something I'm just realizing...I have a lot of friends and offices that have cell phone amplifier / extender systems that only repeat 3G not LTE. With no 3G radio this phone will be only able to do 1x for voice/data?! I think its also crazy that pure data devices such as the MiFi/personal hotspots still include ability to do EvDo Rev A yet phones don't!

jackdubl said:
How new? My S4 gets simultaneous voice/data on lte, but not on 3g. Are you sure you're right about this?
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The S4 had extra antennas unlike the newer phones because of VoLTE. The S4 had both radios on at the same time which eats more battery on a call with VoLTE you have improved battery life during a call and do both at the same time. The move was intentional to save costs as well as battery life in the long run.
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I just got my Nexus 5X up and running on verizon. With my Galaxy Nexus I was about to take a phone call while tethering, but can't do that on this phone. Is there a fix for this? It's kind of a bummer because I tether often and take phone calls.
Edit: (12/18/2015) I figured it out. Chatted with VZW tech support to enable HD voice feature, and made sure "enhanced LTE mode" was on in settings. Voice+Data work simultaneously now!
Update: (1/19/2016) I have still intermittently had issues with simultaneously voice+data. I started to wonder if it could depend on who you are calling or what tower you are connected to. I powered down my phone and pulled the sim card for a few seconds, then rebooted and it worked again.