Iphone 5S Verizon Data & Voice Simultaneous?

Discussion in 'iOS 7' started by DaNiBuZ, Sep 10, 2013.

  1. macrumors newbie

    Oct 25, 2011
    Any word on whether or not the Verizon 5S (I know they are identical phones) will offer simultaneous voice and data? Searched around but could not find anything definitive either which way.

    Edit: Posted in the wrong forum, mods please move.
  2. macrumors 68030

    Feb 26, 2011
    Cincinnati, OH
    I don't think Verizon updated their network yet. It would have made the news.
  3. macrumors 603


    Apr 30, 2013
    Los Angeles
    The answer would be no. Verizon and Sprint are both CDMA and cannot do voice and data at the same time. It doesn't matter the phone. GSM carriers like AT&T can.
  4. macrumors 68030

    Feb 26, 2011
    Cincinnati, OH
    Actually the technology exists and Verizon has stated that they will upgrade their network to make it happen.

  5. macrumors regular

    Mar 17, 2009
    It has nothing to do with this. Most LTE phones can on Verizon because they use separate radios for CDMA and LTE. The iPhone 5 was notable because unlike older LTE phones on Verizon, it used one radio and could not handle this.
  6. macrumors 603


    Apr 30, 2013
    Los Angeles
    That's news to me. Thanks for the correction.
  7. macrumors Core

    Oct 17, 2011
    So I guess the question is whether or not the 5S (and/or 5C) might change that.
  8. macrumors regular

    Mar 17, 2009
    But you are correct about CDMA not being able to do that. Well...they actually have since found a way around it. I know the HTC Thunderbolt, despite it being an LTE device, could actually do voice and data simultaneously over EVDO. I'm not sure why whatever they did to make that work isn't yet a standard on Verizon/Sprint but it sounds like it isn't far off.
  9. macrumors 6502

    Aug 7, 2007
    Dallas, TX
    I'm pretty sure most LTE phones use dual radios.

    LTE is a GSM standard, but hasn't been implemented to have voice yet. On AT&T when on a voice call your using HSPA for voice and data. On verizon or sprint iPhones you are using Edge for voice which doesn't support data.

    Non-Apple phones on Verizon and Sprint work around this by running two radios at once, one for LTE and one for Voice.

    It's not clear yet if Apple changes this with iPhone 5S but I don't think they did. I can't think of a single LTE phone the size of the iPhone, and don't think there's enough wiggle room to implement the change.

    I could be wrong but from what I understand the antenna has to be set up differently to do it. Because apple uses the metal enclosure as part of the antenna design, and the baseband is monitoring the signal across the antennas to deal with signal attenuation from holding it, there isn't the room for dual simultaneous support.

    I'm sure someone smarter then me will interject and prove me wrong though.
  10. macrumors 6502

    Sep 18, 2007
    LTE is based off GSM/UMTS. UMTS actually encompasses wideband CDMA (WCDMA).
  11. macrumors 65816

    Jul 22, 2011
    Verizon needs to roll out VoIP/LTE (voice over LTE) to do this it has nothing to do with the iPhone specs or baseband chip.
  12. macrumors regular

    Mar 17, 2009
    I know, that was my point on an older post. The last one was about how the HTC Thunderbolt not only let you have the whole dual radio LTE/CDMA bit going on, but also voice and data over 3G only with SVDO. The HTC Evo 4G LTE also did it, and possibly some others.


    Well yeah, that would work too.
  13. macrumors Core

    Oct 17, 2011
    Its actually 1x that is used for voice on CDMA (rather than EDGE which is for GSM). But yeah the basic thing comes down to radios: if there's ate separate ones for LTE and CDMA then voice and data can happen simultaneously, otherwise it won't work (as is the case with iPhone 5).
  14. macrumors newbie

    Sep 30, 2013
    The iPhone 5s uses one model for AT&T, Verizon, and T-Mobile, so why can it not use simultaneous voice and data? :confused:
  15. macrumors 68020


    Jul 9, 2009
    because they use different network technologies.

    ATT/Tmo is gsm
    VZW is CDMA

    As others have said, without dual radios you cannot get voice and data simultaneously on VZW. If you are at home on wifi, you can use data and voice though.
  16. macrumors Nehalem


    Feb 19, 2005
    Hardware for now. It's there, it just needs the hardware or VZW needs to go to VoIP/LTE.

    Nope. But still, some phones do it on the current network.
    Wrong. Some phones on VZW are capable of using voice/data at the same time. Nexus, HTC, etc.

    Yes it does. At least with the iPhones. Either they need to include the necessary hardware or do the upgrade like you said.
  17. macrumors 6502a


    Jul 22, 2011
    New Jersey
    So if Verizon upgrades their network to VoIP/LTE then the 5s will be able to have simultaneous voice and data or no?
  18. macrumors 603


    Dec 2, 2010
    Atlanta, GA
    No, the issue isn't with Verizon's network. It's the phone.
  19. macrumors Core

    Oct 17, 2011
    It's a combination of both, realistically speaking.
  20. macrumors member

    Oct 18, 2011
    From what I've read numerous times, it was a design choice by Apple to keep the phone thinner and also a way to save battery life. The radio they use in iPhone 5 (and probably 5s/5c as well) only works in either CDMA or LTE mode. So when you get a phone call on Verizon or Sprint, it switches to CDMA mode until the call is over, meaning you can't use data.

    Verizon is allegedly working on deploying VoLTE that will finally allow simultaneous voice and data. Not sure if iPhone 5/5s/5c hardware actually supports it though.
  21. macrumors 68040


    Dec 16, 2011
    It's both.

    Currently the iPhone 5S can't do D&V because unlike the other devices, the iPhone 5S only has one radio for CDMA and LTE, whereas devices like the Samsung Galaxy S4 have one radio for CDMA (Talk) and one radio for LTE (Data).

    Once Verizon upgrades their network to VoLTE, which allows you to use LTE as your Talk connection AND your Data connection, the iPhone 5S (and IIRC, the iPhone 5 as well) will be able to do simultaneous voice and data.

    Apple has already made it clear they aren't going to switch to a dual-radio system, meaning the only way we'll see D&V on Verizon/Sprint/Virgin Mobile/other CDMA networks is if they all support VoLTE.

    Personally I think VoLTE is the better solution, as one radio for LTE is more efficient and costs less than having to include 2 radios.
  22. Bearxor, Oct 1, 2013
    Last edited: Oct 1, 2013

    macrumors 6502a

    Jun 7, 2007
    The amount of outdated info in this thread is pretty surprising. You do not need two different radio chips to do voice and data on CDMA. The single chip in the iPhone 5/5C/5S is more than capable of handling it.

    Not being able to do voice and data simultaneously is a purposeful design decision by Apple. LTE requires a two antenna diversity setup. In order to use voice at the same time you need a third antenna. That is true if you use one radio chip or two (like in the old Android phones). The problem is that the iPhone 5/5C/5S only have two cellular antennas. When voice is active, both are in use for Apples dual antenna diversity.

    The only reason it works for AT&T and TMobile (and other GSM providers) is that the protocol is already built in to the HSPA spec. Of course, VoLTE will fix this problem regardless. That's still another year or so away for Verizon. They're trailing now, I believe.

    Anyone interested in a more thorough technical explanation of the antenna setup and the the design choices impact how it works should check out Brian Klug's article from the iPhone 5 launch that covers this very topic. It is unchanged for the iPhone 5C/5S.

  23. macrumors 604


    Jan 8, 2012
    Keep in mind even GSM LTE models cant do voice and LTE data. It will drop back to their 3G network. Regardless you can't blame that on Verizon.

  24. macrumors 601

    Feb 9, 2011
    Seems pretty typical for any topic on any discussion forum site to me.
  25. macrumors newbie

    Aug 9, 2008
    Instead of creating a new topic, I'd thought I post here.

    Will an unlocked verizon cdma 5S being used with Tmobile or AT&T be able to have simultaneous voice and data then?

    It looks like the 5S has the same exact radios with both GSM and CDMA 5S but the CDMA one just has the extra CDMA network.

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