% of users stuck at 3G

Dear experts, considering the ongoing trend of legacy techs switching off, what are your thoughts about the minimal percentage of 3G data users that won’t be able to move to higher level technologies.

If we look at recent data of time spent in different techs in Brazil for example (source: Tutella), we can see that something between 20-30% of subscribers spend time mostly on 3G. Similar information at regulators site (Anatel) - 10-20% of accesses (depending on operator) are from 3G.


Of course, at some locations there is no 4G coverage and some CS users can use GSM or 3G only (networks without VoLTE). But I’m wondering, if we consider the scenario of sufficient LTE coverage, well optimized, and PS traffic only, what would be the percentage of users that won’t leave 3G no matter what.

At our project we saw some users being stuck at 3G due to terminal limitation (2G/3G only), UE configuration problems (LTE not selected as network to camp on); SIM card or perhaps provision limitations, and so on. There are many different reasons. So what would be the percentage of UEs that we will lose to GSM instead of going up to LTE by switching off 3G network. Thinking about two scenarios - city center and rural area - what are your thoughts?