HD Voice for iPhone 5

To me, VoLTE is just a much improved version of Voice Over IP.  AT&T spent billions of dollars on building this:

https://en.wikipedia.org/wiki/IP_Multimedia_Subsystem

and this:

https://en.wikipedia.org/wiki/Rich_Communication_Services

Consider that a lot (almost all?) millennials don't use voice on their cell phones.  Consider that a lot of millennials can't afford new iPhones so they buy old ones on Craigs List.  Maybe AT&T might want to push things like AT&T Call Protect out to a few extra 50 million customers of the future.  Today millennials consider voice a waste of time... relegated to useless telemarketer calls and old people they don't want to talk to.

It would be sad if AT&T spent billions of dollars on infrastructure that is going to be used less and less.

If I had spent several billion dollars on a new infrastructure and was told I could get 50 million users by supporting older phones... I might seriously consider it.

Glimmerman,

Apple does not support the Settings, Cellular section of iOS.  That is strictly AT&T's responsibility.  Yes... Apple and AT&T have a lot of serious negotiations of exactly how voice calls and text messages are handled.  Obviously AT&T has got to be concerned because they seem to have less value to add to the smart phone experience as time goes by.  Somehow AT&T has talked Apple out of doing any serious phone-call-screening technology - I can't imagine how.  Obviously it took some serious compensation of some sort to hold Apple back.

And now AT&T is attempting to finally pull something together with AT&T Call Protect - which is a very weak screening app - but, I assume is just the first step.  AT&T Call Protect requires AT&T VoLTE.

Let face it, after a 1-800 or some other marketer phone number prefix is used for a few weeks, that number is permanently blocked by several million people.  It is permanently burned and has no value ever again.  AT&T has to do something.  Recently, tele-marketers have started using local phone numbers.  Now we have local phone numbers that are permanently burned because they are permanetly blocked on hundreds of thousands of smart phones.  The situation is completely out of control.  AT&T has just a couple of years to get in front of the situation or the whole voice/text network is going to become useless because so many numbers are permanetly blocked on so many phones.  I probably have almost a thousand phone numbers blocked on my iPhone and the number is increasing quickly.  Marriot Hotels alone has gone through dozens of local phone numbers that I have had to block.  These numbers are permanetly blocked on my iPhone and cannot be used to call me for the remainder of my life.

If AT&T doesn't fix the situation the only way you will be able to get in touch with someone is with a certified USPS letter.

I have signed up on AT&T prepaid several years ago and just recently bought an AT&T branded Samsung S6 which does support Enhanced LTE Services including HD voice (it's enabled in the mobile network menu).
Whenever I make a call, the connection drops back down to a regular 4G, which by the way has terrible coverage in my area, while LTE is strong.
Is it really that hard to offer VoLTE service to prepaid customers, and in the process saving bandwidth on the old 4G network?
I'm seriously considering switching to Tmo prepaid because they DO in fact offer VoLTE service even on prepaid, as I have actually tested it on a friend's phone.
So listen up AT&T, VoLTE for prepaid or a lost customer(s). Your choice, while I DO have a choice.

Thanks for your consideration.
Bill

At least don't mislead others into thinking that Du Caller is or like HD Voice!!

In fact it has nothing to do with HD Voice, which is a technology to carry voice calls over LTE channels.

If you're affiliated with Du Caller or trying to advertise it, then not on here.

It has sent me on time wasting goose chase, which turns out to be totally useless.

Folks, keep moving along...

@BillAnt   DU caller or Hiya are substitutes for Call Protect, Which is why the OP wants HD voice.