BT landline to VoIP migration

Does anyone know how BT migrate people with landline phones onto VoIP, in advance of the PSTN switch-off? For example, do they:

a) supply an ATA box?
b) supply a replacement IP phone?
c) supply a replacement router with phone socket and built-in ATA?
d) leave punters to sort something out for themselves?
e) something else?

Do people have any choice how it's done?
Is it all free? If not, what charges are made?

(I'm not planning to do this myself, but I have (or had, pre-covid) a number of older folks in my village that I helped when they had PC problems. I can envisage that when the migration starts happening here, I'm going to be contacted by some of them for assistance, so I want to be prepared.

More background: some people are going to have difficulty learning to use any new kit, and will prefer if possible to keep their existing familiar DECT, or in some cases corded POTS, phones. Their needs are basic phone calls only, they will not want any whizzy new features. Some also have telecare devices which use landline. I think all are either currently with BT directly, or have broadband/phone packages from an ISP that sells BTW services.)

In the case of BT customers, very simply the change from PSTN to their ‘Digital Voice’ service is via item (c) on your list. There is no other alternative for BT customers - unless of course they opt to move (their landline/voice service) by porting their ‘landline’ number to another voice (over IP) provder, in which case the other alternatives you note are possible, and indeed more.

Should be noted that if considering doing the latter above with BT - that is porting the PSTN number and /moving to another voice provider (where landline voice is bundled within the same BT contract as broadband) has the effect of ceasing the underlying line, so care must be taken to avoid disruption to the whole service.

Otherwise with a BT migration to their Digital Voice the customer should be able to disconnect their handset from the wall and simply re-connect to the analogue port on the BT Smart Hub router. Dial tone is generated locally on the SH, but otherwise the service should behave the same. Noting that full area codes need to be used in dialling out.

Much has recently be written on the forums about powering the router (and ONtT for FTTP connected properties) in the case of power disruption. Any vulnerable customers should make clear to BT (or whoever provided their landline) that they need to have local power backup for the router/and ONT (where present) - BT are responsible for providing a backup power unit for such vulnerable customers.

Other customers, who are not considered to be vulnerable customers for these purposes, may still wish to provide their own small UPS / backup power unit - such as this small battery backup unit from Eaton which costs under £50

To expand on that a little...

You can move any existing corded or DEC base connection from the existing master socket to the phone socket on the BT Smart Hub 2, info here https://www.bt.com/help/landline/digital-voice-migra...

There are also some BT DECT handsets available and a DECT-to-POTS adapter, info here https://www.bt.com/help/landline/digital-voice--will...

This only applies to BT Retail, and I expect that Plusnet being part of the BT group will eventually launch the same. Any other ISP seliing Openreach WLR products will have to do something else, either develop their own platform or resell a wholesale / white label product from an existing VoIP provider. I know that Andrews & Arnold and Zen Internet both have broadband and VoIP products available, although neither are mass-market ISPs. Sky have a similar migration process with a phone socket on the Sky Broadband Hub which will replace their use of MPF rather than WLR.

Another thing to be aware of is that local dialling is being withdrawn so the full STD code has to be dialled for local numbers too. This is already the case for some area codes due to lack of available numbers rather than being specifically to do with migration to VoIP. I don't know about the BT SH2 handsets but many other existing DECT base/handsets have options to automatically prefix an area/STD code so the end-user experience can remain unchanged.

For the Telecare customers, they should just contact their local Telecare provider as they already have plans to provide alternative kit.

Some might be offered a 4G box with exactly the same functionality as the current one if there is a mobile signal. Others may just be offered an adapter to plug the old gear into the new BT kit. Assistance and equipment should be free.

This will all be immensely re-assuring to people in the north of the UK who had been without power for a week!

In reply to a post by Pheasant:

such as this small battery backup unit from Eaton which costs under £50

I see that particular model only has a rated capacity of 2200mAh, which assuming 3.7V lithium cells is 8.1Wh. It might power a router and ONT for for 30 to 60 minutes if you're lucky; that will go down as the cells age.

If you have a decent mobile signal where you live, then a mobile phone may be a better bet for emergency calls.

Happy Sunday bud. Did I say something to offend you?

Not offended at all, just pointing out reality.

"Other customers, who are not considered to be vulnerable customers for these purposes, may still wish to provide their own small UPS / backup power unit - such as this small battery backup unit from Eaton which costs under £50 ?"

Happy Christmas.

Thanks for replies and links. That makes it all clearer.

I haven't come across the SH2 in the wild, but then I haven't been able to be in people's homes much for the last 18 months. Presumably it is fairly new? I note it supports DECT - are there likely to be any issues plugging an existing DECT master into it? I think >1 master on a DECT network is OK, and presumably handsets registered with the old master stay registered with that unless reregistered? So no issues with phonebooks not transferring, etc.

I also see that the SH2 appears to be locked to BT Broadband. I thought Ofcom had recently banned that - or was it just mobiles that can't be locked any more? If it is locked, then presumably other providers will have to do something equivalent.

Is there any official definition of "vulnerable customer" anywhere? Or is that down to the interpretation of individual providers? I believe also that the Ofcom mandate to provide access to emergency services applies only to the "999" services, and not to carers, telecare providers and so on?

In reply to a post by mikejp:

just pointing out reality.

When talking about reality we should always expect the unexpected which is virtually impossible to plan for but Pheasant's suggestion is a good starting point for a typical outage that happens for a few hours from time to time.

He could have said tell them to get a generator and transfer switch but who's to say the property would have a roof after any high winds so maybe he should have suggested a contingency bunker fully ready to go.

And a happy New Year.

Extraordinary circumstances, terrible for those people - but other than a battery backed solar array or autonomous generator I don’t know of any backup power solutions that will run autonomously for a week.

Seasons Greetings.

Indeed chap. I’m happy to suggest a sliding scale of backup solutions, but didn’t really think it appropriate (as a closing remark at one in the morning) necessarily in light of the OP’s original question. It wasn’t meant to be a treatise on backup power solutions.

Ofcom guidance from 2018 (still current I believe) is here:

https://www.ofcom.org.uk/__data/assets/pdf_file/0016...

The assessment related to ‘at risk’ (I said vulnerable in my reply but unless any QCs amongst us are willing to split the difference…means the same thing) customers is effectively down to the communications provider to undertake at signup or throughout the term.

As far as I’m aware (happy to be corrected) there remains no formal definition or process defined by Ofcom. It’s down to the CP to make a judgement call on which of their customers is ‘at risk’ at the outset of the contract or indeed becomes ‘at risk’ during the period of service. Bit wooly but there you go.

People who have internet and phone service will, in all probability, just have their service changed seamlessly..
However, for technophobes, like my brother-in-law, who have no interest in mobile phones or internet, will be fazed by the changes needed. Especially when the router fails.
There are others who cannot get the internet?
Personally I have kept internet and phone separately away from BT. When the time comes will change to their cloud service. Also will have mobile phone back up storage chargers in the case of power failure.

In reply to a post by candlerb:

In reply to a post by Pheasant:

such as this small battery backup unit from Eaton which costs under £50

I see that particular model only has a rated capacity of 2200mAh, which assuming 3.7V lithium cells is 8.1Wh. It might power a router and ONT for for 30 to 60 minutes if you're lucky; that will go down as the cells age.

If you have a decent mobile signal where you live, then a mobile phone may be a better bet for emergency calls.

Got one here on test...

Currently running a CRS-305-1G-4S. Been running 1 hour and 23 minutes so far and looks like there is plenty of capacity left. I'll run it till it dies and let you know.

Also have a spare N330A-IP DECT base kicking around, so will test on that too; talk time and standby time.

I don't do BT, so cant check with a SH2 unfortunately.

In reply to a post by flippery:

People who have internet and phone service will, in all probability, just have their service changed seamlessly..
However, for technophobes, like my brother-in-law, who have no interest in mobile phones or internet, will be fazed by the changes needed. Especially when the router fails.
There are others who cannot get the internet?
Personally I have kept internet and phone separately away from BT. When the time comes will change to their cloud service. Also will have mobile phone back up storage chargers in the case of power failure.

For when the smartphones and power packs all die…good old no frills 2G mobile phone backup: like one of these in the cupboard, £15 from Argos: 3 hours talk time / 130 hours standby time…ought to be good for as long as the mast is stood up. Hmmm. I suppose there’s always the FM radio for outside company too. Just need to remember to charge it periodically and keep the SIM alive.

Folks with Starlink and their own backup / standby generation, could theoretically carry on comms etc…as long as the dish wasn’t blown away or hit by lightning 😬

In reply to a post by Pheasant:

For when the smartphones and power packs all die…good old no frills 2G mobile phone backup: like one of these in the cupboard, £15 from Argos: 3 hours talk time / 130 hours standby time…ought to be good for as long as the mast is stood up. Hmmm. I suppose there’s always the FM radio for outside company too. Just need to remember to charge it periodically and keep the SIM alive.

I have something similar
Have a reminder to have it depleted then charged every 2 months, and a cheap GiffGaff SIM in it.

However, will only be useful until 2033 when they switch off the old networks

In reply to a post by MilesR:

However, will only be useful until 2033 when they switch off the old networks

Then you'll need one of these, only £35 today, I suspect more choice in the next 12 years

Edited by jchamier (Sun 19-Dec-21 15:37:51)

In reply to a post by Thaumaturge:

I haven't come across the SH2 in the wild, but then I haven't been able to be in people's homes much for the last 18 months. Presumably it is fairly new? I note it supports DECT - are there likely to be any issues plugging an existing DECT master into it? I think >1 master on a DECT network is OK, and presumably handsets registered with the old master stay registered with that unless reregistered? So no issues with phonebooks not transferring, etc.

End of 2018 I believe. DECT handsets are registered to a particular base and there isn't a problem with multiple bases in the same vicinity as the DECT wireless protocol has ten channels available. Each base and paired handsets is its own little enclave, you can page the individiual handsets, synchronise phonebooks, etc. only within that enclave.

I also see that the SH2 appears to be locked to BT Broadband. I thought Ofcom had recently banned that - or was it just mobiles that can't be locked any more? If it is locked, then presumably other providers will have to do something equivalent.

The routers provided by the larger ISPs are usually locked to them as they have built-in remote provisioning, management and monitoring to simplify setup and support.

Unlike mobile phones you are not buying a router, it is provided "free", albeit with a delivery charge, to deliver the service. If you leave an ISP they may require you to return it, or offer to recycle it. Depending on the chipset and how locked-down routers are they are sometimes reusable by replacing the stock firmware with OpenWrt or similar if you are so inclined.

The converse is also true with BT Retail Digital Voice - you have no choice but to use the SH2. They will not make details of the voice setup available for you to use your own ATA, IP phone or phone system, they are providing a fully-managed service to simplify support so if you need anything else you have to choose a different ISP.

Edited by tdw42 (Sun 19-Dec-21 15:58:47)

At least these
https://www.amazon.co.uk/Anker-PowerCore-Technology-...
Should give mobile phone availability for a week for only £50

In reply to a post by MilesR:

In reply to a post by Pheasant:

For when the smartphones and power packs all die…good old no frills 2G mobile phone backup: like one of these in the cupboard, £15 from Argos: 3 hours talk time / 130 hours standby time…ought to be good for as long as the mast is stood up. Hmmm. I suppose there’s always the FM radio for outside company too. Just need to remember to charge it periodically and keep the SIM alive.

I have something similar
Have a reminder to have it depleted then charged every 2 months, and a cheap GiffGaff SIM in it.

However, will only be useful until 2033 when they switch off the old networks

Yeah my old SonyEricsson T630 is getting a bit iffy now in the battery department, so I splashed out and got that Alcatel as the emergency mini brick.

In reply to a post by Pheasant:

Ofcom guidance from 2018 (still current I believe) is here:

https://www.ofcom.org.uk/__data/assets/pdf_file/0016...

The assessment related to ‘at risk’ (I said vulnerable in my reply but unless any QCs amongst us are willing to split the difference…means the same thing) customers is effectively down to the communications provider to undertake at signup or throughout the term.

As far as I’m aware (happy to be corrected) there remains no formal definition or process defined by Ofcom. It’s down to the CP to make a judgement call on which of their customers is ‘at risk’ at the outset of the contract or indeed becomes ‘at risk’ during the period of service. Bit wooly but there you go.

About a year ago my power supplier marked me down as a 'at risk' person due to my then dodgey hip and having a long term 'fit note', TalkTalk wouldn't, they required me to be in receipt of DLA

In reply to a post by burble:

they required me to be in receipt of DLA

I hope they realise DLA is majority replaced by PIP ?

Thaumaturge

Only thing to add to others comments is, you have to persuade them NOT to turn the Router / ONT off at the socket.. This will be a major difference to some old people.

In reply to a post by kitcat:

Thaumaturge

Only thing to add to others comments is, you have to persuade them NOT to turn the Router / ONT off at the socket.. This will be a major difference to some old people.

Yes, I'm well aware of that from personal experience. As I've mentioned elsewhere, towards the end my mum who lived alone suffered from dementia, and out of the blue at one point decided to go round unplugging everything at night. Thia included her cordless phone, which then sat and discharged on its base. Of course she never remembered to plug it back in again next day, so her phone was useless. There was a corded one on the hall table, but she couldn't hear that. I had to wire and gaffer tape the power plug into its socket to stop her doing it.

In reply to a post by Pheasant:

In reply to a post by candlerb:

In reply to a post by Pheasant:

such as this small battery backup unit from Eaton which costs under £50

I see that particular model only has a rated capacity of 2200mAh, which assuming 3.7V lithium cells is 8.1Wh. It might power a router and ONT for for 30 to 60 minutes if you're lucky; that will go down as the cells age.

If you have a decent mobile signal where you live, then a mobile phone may be a better bet for emergency calls.

Got one here on test...

Currently running a CRS-305-1G-4S. Been running 1 hour and 23 minutes so far and looks like there is plenty of capacity left. I'll run it till it dies and let you know.

Also have a spare N330A-IP DECT base kicking around, so will test on that too; talk time and standby time.

I don't do BT, so cant check with a SH2 unfortunately.

As above I ran the test on a little Mikrotik CRS-305-1G-4S using the Eaton mini UPS to hold it up and got a fairly respectable 3 hours 17 minutes and 51 seconds before the Eaton gave up.

I will have to measure the exact power consumption of the MikroTik when its at idle - but from what I've read it here should be 10 watts in idle, with a max. observed of 13 watts.

Unfortunately I've not been able to test the Gigaset N300A IP DECT base with this UPS as none of the supplied DC barrel tip will fit the N300's power input port. I will have to either splice the lead from the plug pack or make an small adapter lead up with a female to male barel adapter arrangement. So for now I cant say how long it would hold up the N300A.

At some point I may rig it up to an Openreach 1+1 ONT and give that a try.

On closer inspection the Gigaset N300A IP uses a not really typical 6.5 VDC input (600mA rated plug-pack). So on reflection probably not a wise idea to plug the Eaton directly as the lowest voltage it can supply is 9VDC…

So it’s going to require a small DC-DC buck converter, so no magic smoke ensues from the N300A base 😂. I’ve found a half decent one on the Pi Hut website. About a tenner including postage:

https://thepihut.com/products/dc-dc-power-module-25w

This could be useful with other devices that don’t use any of the more standard voltages (9, 12, 15 or 19 VDC) from the Eaton.

Will be interesting to see how much power the N300A base actually draws - should be very low as the standard mains plug pack is barely rated for 4 watts. Expect it should be about 2 watts…will drop it on a bench power supply to see what it draws.

The N300A IP manula suggest 1.2W standby and 1.3W during a call so just under 200mA average.

Thanks MHC. So far am measuring

- 0.735 W (113 mA) with nothing connected at idle
- 0.949 W (146 mA) connected to ethernet network

No handsets active/currently registered. Will need to test with some active calls, but very low draw so far.

In reply to a post by jchamier:

In reply to a post by burble:

they required me to be in receipt of DLA

I hope they realise DLA is majority replaced by PIP ?

They might have said DLA or PIP, either way I had just mentioned it in passing whilst on the phone to them, wasn't that worried as my disabilities should have been temporary (they lasted much longer due to cv-19 messing up the health service), I expect that there may be other ways to be listed as vulnerable if you are persistent, but that was the reply I was given.

Pity it doesn't accept PoE as an alternative power source for a UPS-backed PoE switch solution. I know it is less efficient power-wise, but nevertheless useful if power needs distributing to a few locations.

Yealink do on their VoIP bases but AFAIK they don't have an equivalent to the N300 with a POTS connection - only VoIP supported.

Yeah even as they stand I think they're great little units. Been around forever too. Quite surprised by how little power they actually draw. I've been logging it most of the afternoon, with and without calls - its not come close to drawing 1W.

In reply to a post by tdw42:

Pity it doesn't accept PoE as an alternative power source for a UPS-backed PoE switch solution. I know it is less efficient power-wise, but nevertheless useful if power needs distributing to a few locations.

Yealink do on their VoIP bases but AFAIK they don't have an equivalent to the N300 with a POTS connection - only VoIP supported.

I tried to find that out without success, do you know what spec they are? HAve a few 24v & 48v injectors spare and I can then reinstall mine in a better location.

According to the datasheet: Power over Ethernet (IEEE 802.3af), Class 1.

As no negotiation for greater power (802.3at or 802.3bz) is required a passive 48V PoE injector should also work if the Yealink accepts both Alternative A and Alternative B (a.k.a. Mode A and Mode B). The powered device (PD) should accept both so will operate from power sourcing equipment (PSE) providing either, some manufacturers skimp and this is not the case (and also doesn't apply for passive PoE, often 24V, such as that used by Mikrotik and Ubiquiti).

The data/spec sheet I have here does not show it ... I have a few spare injectors, passive and AF and will give it a try! Recently got 4xUbiquiti AF injectors for £7!



And yes, Ubiquiti can be a nuisance, most Unifi uses 48v in some form, but their AirMax is 24v so with remote cameras over a radio link, inline 48-24 adapters are needed (or additional PoE injectors).

I was looking at https://www.yealink.com/upfiles/products/datasheet/Y... https://www.yealink.com/upfiles/products/datasheet/Y... and https://www.yealink.com/upfiles/products/datasheet/Y...

Those injectors were an absolute bargain at that price.

Thanks, W60B is what I have but te documentation supplied does not show PoE, but your link does. The wallwarts supplied sticks out a long way and are obtrusive.

The injectors were on ebay - took a chance and they are legiotimate, even still wrapped/sealed in the original plastic.

The Gigaset N510 IP Pro does do PoE........ but not POTS - may be an option for those who have gone VoIP already.

In reply to a post by MHC:

Thanks, W60B is what I have but te documentation supplied does not show PoE, but your link does. The wallwarts supplied sticks out a long way and are obtrusive.

The injectors were on ebay - took a chance and they are legiotimate, even still wrapped/sealed in the original plastic.

PoE is my default UPS - handily keeps the WiFi running on the various AP's. WiFi Calling for backup happy days.

In reply to a post by Pheasant:

In reply to a post by Pheasant:

In reply to a post by candlerb:

... nested quotes trimmed ...

I see that particular model only has a rated capacity of 2200mAh, which assuming 3.7V lithium cells is 8.1Wh. It might power a router and ONT for for 30 to 60 minutes if you're lucky; that will go down as the cells age.

If you have a decent mobile signal where you live, then a mobile phone may be a better bet for emergency calls.

Got one here on test...

Currently running a CRS-305-1G-4S. Been running 1 hour and 23 minutes so far and looks like there is plenty of capacity left. I'll run it till it dies and let you know.

Also have a spare N330A-IP DECT base kicking around, so will test on that too; talk time and standby time.

I don't do BT, so cant check with a SH2 unfortunately.

As above I ran the test on a little Mikrotik CRS-305-1G-4S using the Eaton mini UPS to hold it up and got a fairly respectable 3 hours 17 minutes and 51 seconds before the Eaton gave up.

I will have to measure the exact power consumption of the MikroTik when its at idle - but from what I've read it here should be 10 watts in idle, with a max. observed of 13 watts.

Unfortunately I've not been able to test the Gigaset N300A IP DECT base with this UPS as none of the supplied DC barrel tip will fit the N300's power input port. I will have to either splice the lead from the plug pack or make an small adapter lead up with a female to male barel adapter arrangement. So for now I cant say how long it would hold up the N300A.

At some point I may rig it up to an Openreach 1+1 ONT and give that a try.

Well to circle back on this slightly, in the name of presenting all the facts - I checked the actual power draw of the CRS-305-1G-4S and its no where near 10 watts in idle - its actually 3.078 watts (@ 19V input) - measured directly from a DC bench power supply. So not such a good or even remotely close proxy for anything approaching the alleged power draw of a Smart Hub 2 etc...

So that explains why the Eaton battery backup could stand it up for nearly 3.5 hours.

After the post-crimbo port and pudding blowout, I'll sneak a 1+1 ONT onto the bench supply and see how long it stands it up. I've got a spare ONT kicking around - expect the ONT will have consumption closer to 2 W

In reply to a post by adrenalize_:

The Gigaset N510 IP Pro does do PoE........ but not POTS - may be an option for those who have gone VoIP already.

* I confirm that the N510 IP Pro will operate on PoE
* It has no answer phone facility, but then that is provided by my hosted supplier
* No POTS facility but then for some their POTS has already been turned off with the rest of us to follow eventually.

No call log facility provided.

In reply to a post by Pheasant:

After the post-crimbo port and pudding blowout, I'll sneak a 1+1 ONT onto the bench supply and see how long it stands it up. I've got a spare ONT kicking around - expect the ONT will have consumption closer to 2 W

My ONT 1 W on initial power up, a quick blip to 3.2 W, then settles in at 2.1 W once it had synched in. I did wonder if it might vary with data going throu, but stayed at 2.1 W during a speed test.

Thanks for that burble. Was that one of the more recent Huawei or Nokia ONTs without the voice port?

[Merry Christmas]

In reply to a post by Pheasant:

Thanks for that burble. Was that one of the more recent Huawei or Nokia ONTs without the voice port?

[Merry Christmas]

Yes it's a Huawei without voice port. Need to get around to checking actual power used by router and phone.

Edited by burble (Sat 25-Dec-21 23:13:29)

In reply to a post by trolleybus:

In reply to a post by adrenalize_:

The Gigaset N510 IP Pro does do PoE........ but not POTS - may be an option for those who have gone VoIP already.

* I confirm that the N510 IP Pro will operate on PoE
* It has no answer phone facility, but then that is provided by my hosted supplier
* No POTS facility but then for some their POTS has already been turned off with the rest of us to follow eventually.

No call log facility provided.

Common firmware base / version numbers for both the N510 and N300 boxes.

The N300 doesn't have any call logging either (not from the GUI anyhow) - its all done on the handsets or at a pinch check the call logs directly with VoiP service provider, if centralised list in needed.

In reply to a post by Thaumaturge:

I haven't come across the SH2 in the wild, but then I haven't been able to be in people's homes much for the last 18 months. Presumably it is fairly new?

Launched in November 2018 - https://www.ispreview.co.uk/index.php/2018/11/bt-lau...

Almost certainly about to be superceded in 2022 with the Smart Hub 3. Only reason I suspect this hasn't already happened is due to Covid related delays.

https://www.ispreview.co.uk/index.php/2021/02/first-...

Silicon shortage.

But is there not talk of 2G ending about the same tme.

In reply to a post by bsg017:

But is there not talk of 2G ending about the same tme.

Not sure we're on the same wavelength on this...

I'm referring to the shortage of capacity at the largest silicon fabs and foundries around the world - resulting in prolonged delays to general chip manufacturing and hence consequential delays to all other products which require those semiconductors in their assembly.

No one quite knows when that particular supply chain will be brought back into equilibrium, possibly sometime in late 2022 or even 2023 depending on whom you read / listen to.

Edit - apologies I see now that you were referring to a post further up the thread, rather than my last.

Edited by Pheasant (Mon 27-Dec-21 13:41:24)

In reply to a post by bsg017:

But is there not talk of 2G ending about the same tme.

Doesn't matter, in many cities you'll find no capacity to make a 2G call already.

In reply to a post by bsg017:

But is there not talk of 2G ending about the same tme.

3G is going to be phased out soon'ish, reusing that spectrum for 4G or 5G.

I can't see 2G going any time soon. It's necessary for wider coverage for Voice calls.

Currently I believe the networks have until 2033 to sunset 2G and 3G but as I said 3G will go 1st.

In reply to a post by j0hn83:

3G is going to be phased out soon'ish, reusing that spectrum for 4G or 5G.

over 50% of it has already on most networks, reducing the old Dual Carrier HSPA (DC-HSPA) upto 42Mbps down to 24Mbps single carrier, with the remaining used for LTE.

I can't see 2G going any time soon. It's necessary for wider coverage for Voice calls.

There shouldn't be a reason why the technology provides wider coverage, if LTE is on the same frequency and the user device is modern enough (e.g. a £30 Nokia from Argos) then 4G VoLTE should be equal. The only reason this appears to be the case is the number of legacy cell sites left that are 2G only on some networks.

Currently I believe the networks have until 2033 to sunset 2G and 3G but as I said 3G will go 1st.

I think thats the agreement with Ofcom/Government, but I agree we will see 3G disappear much sooner, probably before 2023.

2G capacity has been significantly reduced in the last few years on many networks, as 4G can handle more voice calls per Mhz of spectrum.