5G to VoLTE or 3G

[Techhead]

I’m trying to work out if I have a problem or if my iPhone 12  is doing what it should. 

I was under the impression that when I am in a 5G area and a call comes in then my phone should drop down to 4G and use VoLTE for the call.  (EE doesn’t have 5G Standalone/VoNR)

However what actually happens is that my phone drops to 3G for the call. 

This would obviously be concerning as 3G is being switched off soon. It might also explain why sometimes when I dial it take 30to45 seconds to connect. 

So I wanted to check whether I’ve misunderstood what should be happening (and my phone will then drop to VoLTE when 3G is turned off) 

Notes: Carrier settings 54.0. Tested in multiple areas with good or excellent 5G 4G and 3G. Phone is dual sim and a Vodafone SIM switches to VoLTE. 

[bristolian · Accepted solution]

You are correct to believe your phone should drop to VoLTE for voice calls while 5G is in NSA mode. If you're falling to 3G for voice calls, I would suspect a site or area-specific config issue, out of interest where in the UK are you? And how widespread, geographically, are these symptoms?

If your phone has an option to disable 5G/force 4G - it would be interesting to know if the same thing happens. I seem to recall iOS doesn't allow this.

[Chris_B]

@bristolian   It has the option to turn off 5G and just use 4G

 

[Techhead]

Thanks, I’m in the Bristol area but it also happened on a recent trip to Golborne Manchester. 

Good idea, I’ll change to 4G and see what happens. 

[Techhead]

I’ve spent the last few days looking at this. 

Switching to 4G - I stayed on 4G throughout the call. 

Another phone - put my sim in a Pixel 6. On 5G the phone dropped to 3G for calls. 

I think this confirms that there is a configuration issue as @bristolian says. 

[Leanne_T]

Hi @Techhead 

Thanks for trying this, please call us on 150 and our tech gurus will get this looked into for you. 

Leanne.

[Lobbox]

Did you manage to get this resolved? I'm currently experiencing the same issue with carrier profile version 54 on iOS 16.4.1

My wife also has the same issue on her iPhone on a consumer plan, I'm on a SME plan. We are both using esim, not sure if thats related.

I'm in the Greater Manchester area, I travelled 40 miles away on Sunday where the issue still persisted.

Frustrating thing is, I have a sim from an EE MVNO that can place calls on 4G/5G without a problem.

EE Business Support have told me there is ongoing work near me however I can't see this spanning a 40 mile radius, I'm travelling to Birmingham tommorrow so will test while I'm there.

[Cloudane]

If you only switched to eSIM recently there's been a known problem since early March where you lose VoLTE in the process.  I'm having to get a physical SIM again to get it back.

[Lobbox]

I have been using ESIM since 2018, I started having the VoLTE around the beginning of April. I’m being sent a physical sim although it’s not really an option for me as I use dual sim in my iPhone.

[BPW]

It would not be a concern because your phone would then drop to 2G for calling instead! and 2G will run alongside the other network technologies for some time yet.  you can't manually select to 2G on a recent iPhone but your phone should switch automatically to 2G if no other network is available.