@MI5 wrote:
It certainly won't be working very well that way anytime soon either. But o2 need to make a decision one way or another, and quickly!
Without wanting to give anything away and given I am not part of O2 and am dependent on information I can obtain from O2, etc. and that I am not anouncing, not spreading rumour, etc., just posting what I have been made aware of and which maybe incorrect ... (so read it in that spirit)
O2 should be releasing WiFi Calling late Dec 2015 or early 2016. They seem to have a massive confusion over what they regard as "Apple" WiFi Calling (which they consider already available subject to Apple providing it yet when pressed get vague and pass you to Apple who then confirm that it's mainly down to O2) and what they will be offering as WiFi Calling. I think the confusion is due to poor training and people making (incorrect) assumptions.
However, I understand they are placing high importance of roaming between WiFi and VoLTE without losing an ongoing call. I think in practice the number of circumstances this will happen in is few and limited to e.g. use on London Underground (as people are on a WiFi call travelling on the tube and then walk out of a station. For this limited situation of course they will be walking out of WiFi coverage into 4G coverage. However, most of their customers have probaby only rarely seen O2's 4G (I think I've connected to it only 6 time since being with O2 for many years and only used it once). So for most of us WiFi calling is just making up for poor O2 network coverage (e.g. in home). And most of that customer base will not have VoLTE capable phones.
O2 should regard WiFi Calling and VoLTE as seperate things (and they can take steps to transparently hand over calls in the rare situations where both technologies provide coverage at the same time if they so wish but as a seperate issue).
I suspect part of their thinking (e.g. the London Underground scenario) is that they have unfortunately become rather "London centric". For example, their 1800MHz rollout is mainly focusing on London 1st with other cities to follow. And they perceive WiFi Calling largely as a capacity boost rather than making up for poor/inadequate coverage elsewhere in the UK.
They do have some requirements on then for rural coverage (e.g. 98% of population with LTE coverage by 2017...
