From: theom+news@chiark.greenend.org.uk   
      
   Arno Welzel  wrote:   
   > Chris Green, 2026-02-12 12:38:   
   >   
   > > Arno Welzel  wrote:   
   > >> Chris Green, 2026-02-12 09:38:   
   > >>   
   > >>> Arno Welzel  wrote:   
   > >>>> Chris Green, 2026-02-11 21:48:   
   > >>>>   
   > >>>>> This is suddenly becoming more impportant now that 3G is rapidly   
   > >>>>> disappearing.  My 'no name' tablet used to work fine at home but now   
   > >>>>> it doesn't.  We used to have good 3G coverage here, what we have now   
   > >>>>> is mediocre 4G and my tablet can't do VoLTE with my provider anyway,   
   > >>>>>   
   > >>>>> Being a cheapskate and not being a big mobile/cell user I don't want   
   > >>>>> to spend hundreds of pounds on a new device just to ba able to make   
   > >>>>> phone calls.  My £99 10" tablet is excellent in every way except for   
   > >>>>> its lack of VoLTE support on my (very cheap!) provider.   
   > >>>>   
   > >>>> At Amazon you find cheap 4G phones starting around £40. Of course these   
   > >>>> are then only feature phones and not Android based devices. But for the   
   > >>>> specific need to be able to do phone calls, that should be sufficient.   
   > >>>>   
   > >>> ... and they almost certainly won't do VoLTE or VoWiFi will they?   
   > >>> They certainly aren't listed as such by any of the providers I've   
   > >>> looked at?   
   > >>   
   > >> Without VoLTE these phones wouldn't work at all in modern networks,   
   > >> since GSM is switched off already in many countries and 4G/5G is the   
   > >> only option left.   
   > >>   
   > > Exactly!!!  They wont work.  They'll access 4G data (what for?) and   
   > > that will be about it.  Actually most of them will probably provide   
   > > calls and SMS using 2G won't they?   
   >   
   > No. Supporting VoLTE is *required* in 4G and not an option. Without   
   > VoLTE you can not do phone calls at all in a 4G network.   
      
   The problem is not 'support', it's 'provisioning'.  VoLTE needs to be   
   provisioned by the network in an IMS profile.  If the network decides not to   
   send the profile then VoLTE isn't activated.  If the network hasn't   
   whitelisted the phone model (which a no-name from China won't be) then no   
   profile is sent and the phone doesn't active VoLTE.  I've heard that   
   different phone brands provision VoLTE in different ways[1] so how to   
   provision isn't standardised (but I don't know the details).   
      
   GrapheneOS recently added a toggle so you can force provisioning of VoLTE   
   even if the network hasn't sent the profile.  There may be hacks (requiring   
   root) for other brands/OSes, I'm not sure what's out there.  I'm unaware of   
   a phone brand who provides a force-provisioning toggle in their standard OS.   
      
   > Then give the phone back if it does not work and get another one. You   
   > can send the phones back to Amazon if they don't work as expected.   
      
   It's more difficult because you can't always tell if VoLTE is provisioned   
   everywhere.  There's an Android shortcode *#*#INFO#*#* you can dial which   
   tells you if it is, but that may be specific to the towers at a given   
   location and doesn't work on all phones.   
      
   Theo   
      
   [1] Possibly some use IMS and some phone home to a vendor server?  In the   
   latter case the network now has to push their profiles to the phone vendor.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)