Sacrificing the privacy in the interest of finding some insight, I am going to say I live in the UK and I recently transitioned from O2 to Honest Mobile who are chartering their network towers from Three UK. They first sent me an eSIM, but since then I requested a physical SIM to be able to test things. My coverage is extremely poor in most areas. Indoors connection drops to zero most time.
I do not see 4G or 5G. The best I experience is H+. I have transiently saw 4G usually after unlocking the phone, but it drops to H+ almost instantly.
According the various coverage maps, I should see good connection at home for Three UK but bad at work and the opposite with O2. This is indeed my experience, but it’s surprising that connection drops indoors so dramatically and that H+ is the best I get on FP5, which should be better than my old Blackberry. That was not the case with O2, where I regularly saw 4G/5G in the right places and could receive phone calls indoor.
Can I ask you for advice on how to debug this issue further? Specifically, can I ask you how to check:
is there anything in the operating system/software which may be blocking my tower connection?
is it possible that my FP5 sustained some damage and I broke some physical component?
After doing some more searching, I may have found the root of the problem. It’s wonderful what a mere write up for a forum does to your problem solving.
Honest Mobile is a mobile virtual network operator (MVNO). Not sure if this is relevant at all, but what is definitely relevant is that Three UK is switching off their 3G. The things which is almost certainly relevant is when Three UK says:
Calls – your device must be 4G Calling – also known as VoLTE – compatible. Some older 4G devices don’t support 4G Calling.
So I go to my “Network and Internet” → “SIMs” → “Honest” and 4G Calling is switched off. I switch it on and suddenly I get 4G+ and full coverage.
Now this is a solution, so I am going to mark it as such, but I would still appreciate if someone comments on why this is necessary.
Without VoLTE/4G Calling, the phone has to drop to the older 2G or 3G network to make calls. If the 2G or 3G networks no longer exist, then there is no network to drop to, so calls can’t work.
VoLTE/4G Calling is the new voice-over-LTE technology, and mobile providers worldwide either have implemented, or will be implementing it, retooling their 2G/3G networks for use with 4G instead.
Note that 4G data/internet is separate from 4G/VoLTE calling technology, which is why you see 4G or LTE at the top of your screen when browsing the internet, and why that indicator changes to H+ or GSM if you make a call without VoLTE/4G Calling enabled.
It’s not. If they use Three UK’s infrastructure, then you’re subject to Three UK’s network requirements. The only difference is that your data speed might be deprioritized/throttled at times. That depends on the MVNO’s agreement with the underlying carrier.