Good thing I braced myself for the Verizon call. I ended up on the phone with three reps for nearly three hours. The Verizon rep who did the main troubleshooting saw firsthand the dropped call problem as it happened several times during our session (thankfully before the fixes).
We did several things, all from the same spot in my apartment where I make most of my calls.
- I toggled my phone settings to AC on (it's been off for a while), HD voice enabled (only possible with AC on), and LTE/CDMA network (it's been on), then turned my phone off. Rep disconnected then reconnected my phone from the line (which he said can help with call quality/signal issues), and reset my AC on their end. We then tested call quality several times with him calling me on the line.
- Tested voice/data when I was on the call with the rep, with AC enabled, wifi on, and cellular data off (this should also work with wifi off and cellular data on, or with both on..)
- Tested wireless calling. For that, had to toggle my settings so cellular data was off, wifi was on, and wireless calling under AC feature was enabled. Not sure why cellular data needs to be off before you can enable wifi calling, but the rep said the phone will only make wifi calls when cellular data is off, and there's no way to otherwise 'force' a wifi call. Might try to test this later.
After we reset my AC, call quality was notably better for me with the rep coming through clearly and with minimal interference. But the rep said that the call quality was just 'okay' on his end (better than before, but still not stellar). And after the reset, when I was getting out of my chair, he suddenly couldn't hear me well and said there was lots of interference. :-(
Sound volume via the earpiece seemed to be comparable if not a tad worse than before the reset - I had to strain to hear the rep even at full volume. When on speakerphone, volume was more than adequate and perhaps better than before the reset, but the rep reported that I sounded far away and it was much better when I took him off speakerphone.
So bottom line, with the AC reset the call quality was noticeably better on my end (only a tad better on the other person's end); and call volume was comparable if not a tad worse via the earpiece (maybe better than before via speakerphone). At this point, the rep said the only remaining solution he could think of was switching out SIM cards, so we're going to try that.
Re: voice/data, we got it to work but I first had to access the internet, then make the call. When I made the call without first accessing the internet, then tried to access the internet during the call, I got an error messaging saying I had no internet connection. Odd.
Re: wireless, I'd say this was the win. It worked very well in my apartment, where my download speeds range from 40-60 mbps. Calls seemed clearer with less interference than when using 4G/LTE after the AC reset. Volume via the earpiece seemed a tad louder; speaker volume was more than adequate, as it was using 4G/LTE with AC reset. Unfortunately, according to the rep there's no default setting where the phone will revert to wifi calling when certain conditions are met, so if you're using cellular most of the time, you have to reset the phone each time you want to use wifi.
I'm going to likely use wifi calling most of the time when home, and will test it in other spots to see how it holds up. I'll also continue to test 4G/LTE calling with the AC reset, just to see how it's working over time and in different places.
EDIT: Wifi calling ths morning seems to be a tad patchier than last night, but still acceptable (maybe on par with 4G/LTE post-reset). My wifi download speed is still showing 50+mbps, so not sure what's up.