Bubbles121
ULTIMATE Member
I think this is a lesser talked about topic but I'd like to know other people's experiences. As I'm sure many of you know I'm a primarily Three user, albeit via Smarty. Three, Smarty, iD and Superdrug all use the same IMS service, as do Vodafone, Lebara, Asda and Voxi so these all come under their MNO in terms of call quality. I believe 1p, EE and (now dead) BT all share the same too. The only variation is O2. O2 it's self has decentish support for HD (AMR-WB) calling, even via 3G. However, the only MVNO it shares it's IMS services with is Tesco so Sky and Virgin run their own. Sky and Virgin do NOT support HD calling at all, for both 4G and 3G calls. Virgin don't even allow VoLTE by default, but I think that's because their IMS service is so dodgy they'd rather people who didn't know about it not use it.
These are the combos I know so far that work for HD (AMR-WB and EVS where possible, EVS is only host to host for the time being).
AMR-NB is a standard, old Non HD call.
AMR-WB is the first rendition of HD calling which works inter network. It offers good call quality (a huge step above NB) and much higher bitrates.
EVS (Stands for Evoluted Voice Services) only works for EE to EE calls, Three to Thee calls and Vodafone to Vodafone calls. It offers CD like audio quality and is the best you can get. These calls sound like the person is in the room with you - EVS calls require a supported device and network to function accordingly.
AMR-NB calls show a "phone" icon on Samsung devices next to the call time and nothing next to the call time on any other Google phone based devices.
AMR-WB calls show "HD" next to the time on Samsung and Google phone based devices.
EVS Calls show "HD+" next to the time on Samsung devices and Google Phone based devices show "HD" again next to the time (it doesn't differenciate between EVS and AMR-WB on Google phone based devices).
S20 Series and above support EVS, A series devices don't support.
iPhones don't differenciate at all between all of the 3 calling protocols but EVS IS supported from the iPhone 11/SE 2 and above.
Most Xiaomi devices support afaik as long as they have VoLTE. Nothing phone 1 also seems capable.
THREE
Three -> Three (EVS so CD like call quality)
Three -> Vodafone (AMR-WB - HD)
Vodafone -> Three (AMR-WB - HD - this has only been recently enabled so is a nice touch)
O2/Tesco/giffgaff -> Three (AMR-WB - HD, even when using 3G calling)
Three -> O2/Tesco/giffgaff (AMR-WB - HD, even when using 3G calling).
Three -> EE (AMR-WB - HD)
EE -> Three (NOT HD, AMR-NB)
EE (Including 1p, BT & Plusnet)
EE -> EE (EVS)
EE -> Three (NOT HD - AMR-NB)
Three -> EE (AMR-WB, HD)
Vodafone UK (including Lebara, TalkMobile and VOXI)
Vodafone -> Vodafone (EVS, recently enabled)
Vodafone -> Three (AMR-WB - HD)
Three -> Vodafone (AMR-WB - HD)
O2 -> Vodafone (AMR-WB - HD)
Vodafone -> O2 (AMR-WB - HD)
O2-UK (Including giffgaff and Tesco Mobile)
O2 & Tesco VoLTE -> O2 & Tesco VoLTE (EVS, recently enabled)
O2 -> Three (AMR-WB - HD)
Three -> O2 (AMR-WB - HD)
O2 -> Vodafone (AMR-WB - HD)
Vodafone -> O2 (AMR-WB - HD)
This is all that I am aware of so far, so people feel free to fill in gaps where I have missed (which is quite a lot lol)
These are the combos I know so far that work for HD (AMR-WB and EVS where possible, EVS is only host to host for the time being).
AMR-NB is a standard, old Non HD call.
AMR-WB is the first rendition of HD calling which works inter network. It offers good call quality (a huge step above NB) and much higher bitrates.
EVS (Stands for Evoluted Voice Services) only works for EE to EE calls, Three to Thee calls and Vodafone to Vodafone calls. It offers CD like audio quality and is the best you can get. These calls sound like the person is in the room with you - EVS calls require a supported device and network to function accordingly.
AMR-NB calls show a "phone" icon on Samsung devices next to the call time and nothing next to the call time on any other Google phone based devices.
AMR-WB calls show "HD" next to the time on Samsung and Google phone based devices.
EVS Calls show "HD+" next to the time on Samsung devices and Google Phone based devices show "HD" again next to the time (it doesn't differenciate between EVS and AMR-WB on Google phone based devices).
S20 Series and above support EVS, A series devices don't support.
iPhones don't differenciate at all between all of the 3 calling protocols but EVS IS supported from the iPhone 11/SE 2 and above.
Most Xiaomi devices support afaik as long as they have VoLTE. Nothing phone 1 also seems capable.
THREE
Three -> Three (EVS so CD like call quality)
Three -> Vodafone (AMR-WB - HD)
Vodafone -> Three (AMR-WB - HD - this has only been recently enabled so is a nice touch)
O2/Tesco/giffgaff -> Three (AMR-WB - HD, even when using 3G calling)
Three -> O2/Tesco/giffgaff (AMR-WB - HD, even when using 3G calling).
Three -> EE (AMR-WB - HD)
EE -> Three (NOT HD, AMR-NB)
EE (Including 1p, BT & Plusnet)
EE -> EE (EVS)
EE -> Three (NOT HD - AMR-NB)
Three -> EE (AMR-WB, HD)
Vodafone UK (including Lebara, TalkMobile and VOXI)
Vodafone -> Vodafone (EVS, recently enabled)
Vodafone -> Three (AMR-WB - HD)
Three -> Vodafone (AMR-WB - HD)
O2 -> Vodafone (AMR-WB - HD)
Vodafone -> O2 (AMR-WB - HD)
O2-UK (Including giffgaff and Tesco Mobile)
O2 & Tesco VoLTE -> O2 & Tesco VoLTE (EVS, recently enabled)
O2 -> Three (AMR-WB - HD)
Three -> O2 (AMR-WB - HD)
O2 -> Vodafone (AMR-WB - HD)
Vodafone -> O2 (AMR-WB - HD)
This is all that I am aware of so far, so people feel free to fill in gaps where I have missed (which is quite a lot lol)
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