Simultaneous voice and cellular data on the iPhone 6S Plus on Verizon Problem: When the phone rings (regardless of whether I pick up or not, and regardless of whether it's a VoLTE or CDMA call), I lose Internet access over the cellular network (regardless of whether it's 2G, 3G or 4G LTE). I don't have a landline Internet at home, so "use WiFi" is not a solution to the problem.

Specs: 


Verizon iPhone 6S Plus 128 GB (CDMA)
Unlimited LTE cellular data plan with hotspot feature enabled on the account, allowing legal USB, WiFi and Bluetooth tethering as supported by the iPhone's "Personal Hotspot" built-in feature, which is activated by Verizon when they detect that I have Hotspot enabled on my account.
Not Jailbroken. Unwilling to Jailbreak in order to implement a solution to this problem.


For comparison, if I take out my SIM card and put it into any Android smartphone, I can receive a call over VoLTE or CDMA on the same network, at the same physical location, and use LTE data at the same time. So, no, it is definitely not a limitation of the network. The network supports simultaneous data and voice if your data is coming from LTE, which mine always is, even if the call comes in over CDMA at the same time.

And, since the 6S Plus supports VoLTE, you'd think that if the call comes in over VoLTE (which I've specifically tested from an Android phone that is definitely also on VoLTE and has great LTE signal strength), that the data would be able to continue simultaneously, right? Nope. The phone seems to be artificially limiting or killing the data, even though there is nothing inherent in the VoLTE protocol that says you can't do a VoLTE call and a data session at the same time.

How can I solve this?

Possible approaches to a solution that I've investigated:


Is there some setting to change to force it to not disconnect the LTE when receiving a call?
Is there some way to always forward incoming calls on the cell # to a VoIP number (Skype, Google Voice, etc.) so that my cellular # never rings? This will prevent me from taking calls when I have no Internet access on my phone, but that's rare enough that I'm willing to accept that as a consequence.
Lastly, is there a way to keep my LTE enabled but prevent any incoming calls from ringing the phone (and thus disconnecting the Internet)?


My attempts at pursuing these solutions:



  Is there some setting to change to force it to not disconnect the LTE when receiving a call?



None that I've found.



  Is there some way to always forward incoming calls on the cell # to a VoIP number (Skype, Google Voice, etc.) so that my cellular # never rings? This will prevent me from taking calls when I have no Internet access on my phone, but that's rare enough that I'm willing to accept that as a consequence.



None that I can find. All the VoIP things I find seem to do the reverse: they'll forward your incoming VoIP calls to your cellular number. That's not what I want. I want the opposite of that.



  Lastly, is there a way to keep my LTE enabled but prevent any incoming calls from ringing the phone (and thus disconnecting the Internet)?



Do Not Disturb mode may help me with this (?), but I think it would still momentarily "hiccup" the Internet connection, wouldn't it? I think it would, because the phone has to receive the call to decide to ignore it.

Any better solutions out there? This seems like something basic that I took for granted when I had an Android phone, but now that I switched to iPhone for completely unrelated reasons, I'm finding this to be a very annoying limitation that shouldn't be a limitation at all (because the network allows it, and all of Apple's competitors allow simultaneous voice and data, so why won't Apple?), and I'd like to work around it or directly solve it if possible.
You are right when you state that simultaneous data and voice is possible over the LTE connection. There's not a VoLTE-capable network in the world where this isn't the case.

But many of your other assumptions, albeit founded on sound logic, are not consistent with reality.

So here's what you need to know:


Your calls are definitely not occurring over LTE if the data signal drops when you place the call. But your phone is definitely capable of VoLTE (as is Verizon's network).
Your Android phone has two radios in it, which is why you can maintain your LTE data connection while on a phone call on that phone. The vast majority of Verizon-sanctioned LTE-capable Android phones have two radios in them (although we're starting to see some hit the market with only a single radio now that VoLTE is possible). The phone call goes over 1xRTT while the LTE radio maintains data connectivity.


There are several things to check before opening a trouble ticket with Verizon:


Make sure "Voice &amp; Data" is selected in Settings > Cellular > Enable LTE.
Make sure your Verizon account has the feature called "Advanced Calling 1.0" added to it. You can add this through My Verizon yourself (in the same place where you'd activate/deactive the mobile hotspot feature).
Make sure you are using a newer SIM card. Believe it or not, there are old Nano-SIM cards out there that simply will not support VoLTE. If you need a new one, ask Verizon.


If you've done all of this, there's one more thing to know before opening a trouble ticket: your phone will still prefer 1xRTT phone calls over LTE ones if you're in a marginal service area. And when it does this, since no iPhone has ever supported TX/RX with two cell networks simultaneously, your iPhone will drop LTE and hop straight onto 1xRTT to grab the call.

If marginal service is the cause of your problem, then your only solution will be to use a different phone—one that has a dual radio setup. Manufacturers are rapidly moving away from dual radios though, so be careful when purchasing anything new.

Good luck!