A useful map here

https://content.tfl.gov.uk/mobile-coverage-tube-map-september-23.pdf

Uninterrupted 4G and 5G mobile coverage will be rolled out to all
underground station ticket halls, platforms and tunnels on the Tube and
Elizabeth line networks - most (around 80% or up to 220 out of 272
stations) will be connected by the end of 2024.

https://tfl.gov.uk/campaign/station-wifi

A bit more here

https://www.ispreview.co.uk/index.php/2023/09/londons-euston-underground-station-gets-4g-and-5g-mobile.html

Transport for London (TfL) – in partnership with Boldyn Networks – today
confirmed that Euston station on the Charing Cross branch platforms has
today become the latest place on the London Underground to go live with 4G
and 5G mobile (mobile broadband) cover, which customers of EE, Vodafone, O2
and Three UK will benefit from.

NOTE: O2 (VMO2), Three UK, EE (BT) and Vodafone have all signed deals to
harness the infrastructure. The new network is classed as being 5G Ready.

Boldyn Networks (formerly BAI) currently holds a 20-year concession deal
with TfL, which was signed in June 2021 (here) and allows them to build the
new 4G infrastructure and to then make it available via wholesale for
Mobile Network Operators (MNO) to harness, although they won’t all go live
at the same time. The goal of this is to cover the entire London
Underground by late 2024 (ticket halls, platforms and tunnels).

The aforementioned mobile operators have already deployed across the
eastern half of the Jubilee Line and, at the end of last year, they added 6
more stations including Holland Park, Notting Hill Gate, Queensway,
Archway, Tufnell Park, Kentish Town and more. Earlier this month, they were
joined by Oxford Circus and Tottenham Court Road, with coverage extending
across the ticket halls, on the Central Line platforms and within the
tunnel between the two stations.

The latest section of the Tube to get mobile coverage today will allow
those arriving to the city via Euston national rail station from Liverpool,
Manchester, Milton Keynes and Crewe, who then change onto the Tube, to
still access the latest travel information, social media and their emails,
or make calls, and stream videos while using the underground station.

In the next few weeks, the tunnels between Camden Town, Mornington Crescent
and Euston will be connected. This will create consistent mobile coverage
in both the stations and tunnels on the Northern line between Archway and
Euston (Charing Cross branch), a distance of around 3 miles underground.
The platforms on the Bank branch of the Northern line, as well as the
Victoria line platforms at Euston will also get mobile coverage in the
coming months.

Currently more than 10% of Tube stations with platforms that are
underground, and therefore usually unable to get a mobile signal, now have
4G and 5G mobile coverage. When combined with sections of the Tube which
are above ground, this means that around 60% of the whole network has
mobile coverage.

In the coming months, further stations along the Northern and Central
lines, such as Goodge Street, Chancery Lane and Bank will also get mobile
coverage, helping the millions of visitors who come to Central London and
in particular the West End every year better navigate the capital. Boldyn
will also be progressing work to introduce mobile coverage to the southern
end of the Northern line, with the first sections going live during Summer
2024.

By the end of the year, 33 stations with platforms that are underground,
and therefore usually unable to get a mobile signal, as well as connecting
tunnels, will have mobile coverage, increasing to more than 40 stations by
Spring 2024. Due to this, around 500 people are working overnight across
the Tube network to install mobile equipment, with all works needed to be
tidied away before the network opens for customers every morning.

In message <ueuda3$2ffrs$1@dont-email.me>, at 10:55:00 on Tue, 26 Sep
2023, Tweed <usenet.tweed@gmail.com> remarked:

>Transport for London (TfL) – in partnership with Boldyn Networks – today
>confirmed that Euston station on the Charing Cross branch platforms has
>today become the latest place on the London Underground to go live with 4G
>and 5G mobile (mobile broadband) cover, which customers of EE, Vodafone, O2
>and Three UK will benefit from.

And customers of their MVNOs? eg Tesco mobile on O2.
--
Roland Perry

Roland Perry <roland@perry.uk> wrote:
> In message <ueuda3$2ffrs$1@dont-email.me>, at 10:55:00 on Tue, 26 Sep
> 2023, Tweed <usenet.tweed@gmail.com> remarked:
>
>> Transport for London (TfL) – in partnership with Boldyn Networks – today
>> confirmed that Euston station on the Charing Cross branch platforms has
>> today become the latest place on the London Underground to go live with 4G
>> and 5G mobile (mobile broadband) cover, which customers of EE, Vodafone, O2
>> and Three UK will benefit from.
>
> And customers of their MVNOs? eg Tesco mobile on O2.

From what I can piece together by reading various press releases, yes. I’ve
found no definitive reference.

On 28 Sep 2023 19:11:20 +0100 Roland Perry wrote:
>In message <ueuda3$2ffrs$1@dont-email.me>, at 10:55:00 on Tue, 26 Sep
>2023, Tweed <usenet.tweed@gmail.com> remarked:
>
>>Transport for London (TfL) – in partnership with Boldyn Networks – today
>>confirmed that Euston station on the Charing Cross branch platforms has
>>today become the latest place on the London Underground to go live with 4G
>>and 5G mobile (mobile broadband) cover, which customers of EE, Vodafone, O2
>>and Three UK will benefit from.
>
>And customers of their MVNOs? eg Tesco mobile on O2.

Only if it supports VoLTE (aka Voice over LTE, aka Voice over 4g). I use
giffgaff, which doesn't.
--
(Remove numerics from email address)

Dave Royal <dave@dave123royal.com> wrote:
> On 28 Sep 2023 19:11:20 +0100 Roland Perry wrote:
>> In message <ueuda3$2ffrs$1@dont-email.me>, at 10:55:00 on Tue, 26 Sep
>> 2023, Tweed <usenet.tweed@gmail.com> remarked:
>>
>>> Transport for London (TfL) – in partnership with Boldyn Networks – today
>>> confirmed that Euston station on the Charing Cross branch platforms has
>>> today become the latest place on the London Underground to go live with 4G
>>> and 5G mobile (mobile broadband) cover, which customers of EE, Vodafone, O2
>>> and Three UK will benefit from.
>>
>> And customers of their MVNOs? eg Tesco mobile on O2.
>
> Only if it supports VoLTE (aka Voice over LTE, aka Voice over 4g). I use
> giffgaff, which doesn't.

But presumably data still works?

On 28 Sep 2023 20:34:21 -0000 (UTC) Tweed wrote:
>Dave Royal <dave@dave123royal.com> wrote:
>> On 28 Sep 2023 19:11:20 +0100 Roland Perry wrote:
>>> In message <ueuda3$2ffrs$1@dont-email.me>, at 10:55:00 on Tue, 26 Sep
>>> 2023, Tweed <usenet.tweed@gmail.com> remarked:
>>>
>>>> Transport for London (TfL) – in partnership with Boldyn Networks –
>>>> today
>>>> confirmed that Euston station on the Charing Cross branch platforms has
>>>> today become the latest place on the London Underground to go live with 4G
>>>> and 5G mobile (mobile broadband) cover, which customers of EE, Vodafone,
>>>> O2
>>>> and Three UK will benefit from.
>>>
>>> And customers of their MVNOs? eg Tesco mobile on O2.
>>
>> Only if it supports VoLTE (aka Voice over LTE, aka Voice over 4g). I use
>> giffgaff, which doesn't.
>
>But presumably data still works?

I was thinking of whether you might get a normal phone service. I don't
know whether you'd get a data-only service. I can't see why not,
technically.
--
(Remove numerics from email address)

In message <uf4pi2$3ruti$1@dont-email.me>, at 21:00:50 on Thu, 28 Sep
2023, Dave Royal <dave@dave123royal.com> remarked:
>On 28 Sep 2023 20:34:21 -0000 (UTC) Tweed wrote:
>>Dave Royal <dave@dave123royal.com> wrote:
>>> On 28 Sep 2023 19:11:20 +0100 Roland Perry wrote:
>>>> In message <ueuda3$2ffrs$1@dont-email.me>, at 10:55:00 on Tue, 26 Sep
>>>> 2023, Tweed <usenet.tweed@gmail.com> remarked:
>>>>
>>>>> Transport for London (TfL) – in partnership with Boldyn Networks –
>>>>> today
>>>>> confirmed that Euston station on the Charing Cross branch platforms has
>>>>> today become the latest place on the London Underground to go live with 4G
>>>>> and 5G mobile (mobile broadband) cover, which customers of EE, Vodafone,
>>>>> O2
>>>>> and Three UK will benefit from.
>>>>
>>>> And customers of their MVNOs? eg Tesco mobile on O2.
>>>
>>> Only if it supports VoLTE (aka Voice over LTE, aka Voice over 4g). I use
>>> giffgaff, which doesn't.
>>
>>But presumably data still works?
>
>I was thinking of whether you might get a normal phone service. I don't
>know whether you'd get a data-only service. I can't see why not,
>technically.

I make/receive about one voice call a week, so data-only would be
sufficient.

Is there such thing as SMS over LTE, or is it a subset of VoLTE?
--
Roland Perry

Roland Perry <roland@perry.uk> wrote:
> In message <uf4pi2$3ruti$1@dont-email.me>, at 21:00:50 on Thu, 28 Sep
> 2023, Dave Royal <dave@dave123royal.com> remarked:
>> On 28 Sep 2023 20:34:21 -0000 (UTC) Tweed wrote:
>>> Dave Royal <dave@dave123royal.com> wrote:
>>>> On 28 Sep 2023 19:11:20 +0100 Roland Perry wrote:
>>>>> In message <ueuda3$2ffrs$1@dont-email.me>, at 10:55:00 on Tue, 26 Sep
>>>>> 2023, Tweed <usenet.tweed@gmail.com> remarked:
>>>>>
>>>>>> Transport for London (TfL) – in partnership with Boldyn Networks –
>>>>>> today
>>>>>> confirmed that Euston station on the Charing Cross branch platforms has
>>>>>> today become the latest place on the London Underground to go live with 4G
>>>>>> and 5G mobile (mobile broadband) cover, which customers of EE, Vodafone,
>>>>>> O2
>>>>>> and Three UK will benefit from.
>>>>>
>>>>> And customers of their MVNOs? eg Tesco mobile on O2.
>>>>
>>>> Only if it supports VoLTE (aka Voice over LTE, aka Voice over 4g). I use
>>>> giffgaff, which doesn't.
>>>
>>> But presumably data still works?
>>
>> I was thinking of whether you might get a normal phone service. I don't
>> know whether you'd get a data-only service. I can't see why not,
>> technically.
>
> I make/receive about one voice call a week, so data-only would be
> sufficient.
>
> Is there such thing as SMS over LTE, or is it a subset of VoLTE?

I don’t think it needs VoLTE. See here

https://www.sharetechnote.com/html/Handbook_LTE_SMS.html

I’m afraid you are going to have to read it yourself, it’s too involved to
summarise.

I’m assuming the MVNOs that don’t currently offer VoLTE are going to have
to get their acts together soon. There won’t be any 3G to fall back on for
the voice call and 2G is a rapidly shrinking island being maintained mainly
for communicating with embedded devices.

On 29 Sep 2023 11:15:44 -0000 (UTC) Tweed wrote:
>Roland Perry <roland@perry.uk> wrote:
>> In message <uf4pi2$3ruti$1@dont-email.me>, at 21:00:50 on Thu, 28 Sep
>> 2023, Dave Royal <dave@dave123royal.com> remarked:
>>> On 28 Sep 2023 20:34:21 -0000 (UTC) Tweed wrote:
>>>> Dave Royal <dave@dave123royal.com> wrote:
>>>>> On 28 Sep 2023 19:11:20 +0100 Roland Perry wrote:
>>>>>> In message <ueuda3$2ffrs$1@dont-email.me>, at 10:55:00 on Tue, 26 Sep
>>>>>> 2023, Tweed <usenet.tweed@gmail.com> remarked:
>>>>>>
>>>>>>> Transport for London (TfL) – in partnership with Boldyn Networks –
>>>>>>> today
>>>>>>> confirmed that Euston station on the Charing Cross branch platforms has
>>>>>>> today become the latest place on the London Underground to go live with
>>>>>>> 4G
>>>>>>> and 5G mobile (mobile broadband) cover, which customers of EE,
>>>>>>> Vodafone,
>>>>>>> O2
>>>>>>> and Three UK will benefit from.
>>>>>>
>>>>>> And customers of their MVNOs? eg Tesco mobile on O2.
>>>>>
>>>>> Only if it supports VoLTE (aka Voice over LTE, aka Voice over 4g). I use
>>>>> giffgaff, which doesn't.
>>>>
>>>> But presumably data still works?
>>>
>>> I was thinking of whether you might get a normal phone service. I don't
>>> know whether you'd get a data-only service. I can't see why not,
>>> technically.
>>
>> I make/receive about one voice call a week, so data-only would be
>> sufficient.
>>
>> Is there such thing as SMS over LTE, or is it a subset of VoLTE?
>
>I don’t think it needs VoLTE. See here
>
>https://www.sharetechnote.com/html/Handbook_LTE_SMS.html
>
>I’m afraid you are going to have to read it yourself, it’s too involved to
>summarise.

I think that the way SMSs are handled depends on the mobile network
operator. They can be handled like VoLTE or they can be sent directly like
data.

And text messages may not be SMSs. Depending on the sending and receiving
phones and how they're configured they might be Apple iMessages or
Google's RCS.

>I’m assuming the MVNOs that don’t currently offer VoLTE are going to have
>to get their acts together soon. There won’t be any 3G to fall back on for
>the voice call and 2G is a rapidly shrinking island being maintained mainly
>for communicating with embedded devices.

Yes. I see that on Tesco Mobile VoLTE is currently only available on
monthly tariffs.
--
(Remove numerics from email address)

On 28/09/2023 19:11, Roland Perry wrote:
> In message <ueuda3$2ffrs$1@dont-email.me>, at 10:55:00 on Tue, 26 Sep 2023, Tweed <usenet.tweed@gmail.com> remarked:
>
>> Transport for London (TfL) – in partnership with Boldyn Networks – today
>> confirmed that Euston station on the Charing Cross branch platforms has
>> today become the latest place on the London Underground to go live with 4G
>> and 5G mobile (mobile broadband) cover, which customers of EE, Vodafone, O2
>> and Three UK will benefit from.
>
> And customers of their MVNOs? eg Tesco mobile on O2.

I have a phone using Lebara (Vodafone offshoot) which has started to work on some TfL lines, so maybe the answer is yes.

--
Clive Page

In message <uf6d9n$8khm$1@dont-email.me>, at 11:43:51 on Fri, 29 Sep
2023, Dave Royal <dave@dave123royal.com> remarked:
>On 29 Sep 2023 11:15:44 -0000 (UTC) Tweed wrote:
>>Roland Perry <roland@perry.uk> wrote:
>>> In message <uf4pi2$3ruti$1@dont-email.me>, at 21:00:50 on Thu, 28 Sep
>>> 2023, Dave Royal <dave@dave123royal.com> remarked:
>>>> On 28 Sep 2023 20:34:21 -0000 (UTC) Tweed wrote:
>>>>> Dave Royal <dave@dave123royal.com> wrote:
>>>>>> On 28 Sep 2023 19:11:20 +0100 Roland Perry wrote:
>>>>>>> In message <ueuda3$2ffrs$1@dont-email.me>, at 10:55:00 on Tue, 26 Sep
>>>>>>> 2023, Tweed <usenet.tweed@gmail.com> remarked:
>>>>>>>
>>>>>>>> Transport for London (TfL) – in partnership with Boldyn
>>>>>>>>Networks – today confirmed that Euston station on the
>>>>>>>>Charing Cross branch platforms has today become the latest
>>>>>>>>place on the London Underground to go live with 4G and 5G
>>>>>>>>mobile (mobile broadband) cover, which customers of EE,
>>>>>>>>Vodafone, O2 and Three UK will benefit from.
>>>>>>>
>>>>>>> And customers of their MVNOs? eg Tesco mobile on O2.
>>>>>>
>>>>>> Only if it supports VoLTE (aka Voice over LTE, aka Voice over 4g). I use
>>>>>> giffgaff, which doesn't.
>>>>>
>>>>> But presumably data still works?
>>>>
>>>> I was thinking of whether you might get a normal phone service. I don't
>>>> know whether you'd get a data-only service. I can't see why not,
>>>> technically.
>>>
>>> I make/receive about one voice call a week, so data-only would be
>>> sufficient.
>>>
>>> Is there such thing as SMS over LTE, or is it a subset of VoLTE?
>>
>>I don’t think it needs VoLTE. See here
>>
>>https://www.sharetechnote.com/html/Handbook_LTE_SMS.html
>>
>>I’m afraid you are going to have to read it yourself, it’s too involved to
>>summarise.

All I want is an answer to the situation I mention below.

>I think that the way SMSs are handled depends on the mobile network
>operator. They can be handled like VoLTE or they can be sent directly like
>data.
>
>And text messages may not be SMSs. Depending on the sending and receiving
>phones and how they're configured they might be Apple iMessages or
>Google's RCS.

Different messaging platforms are increasingly conflated, but I'm
interested almost exclusively in receiving 2FA SMS, which I don't think
are sent to those other services.

>>I’m assuming the MVNOs that don’t currently offer VoLTE are going to have
>>to get their acts together soon. There won’t be any 3G to fall back on for
>>the voice call and 2G is a rapidly shrinking island being maintained mainly
>>for communicating with embedded devices.
>
>Yes. I see that on Tesco Mobile VoLTE is currently only available on
>monthly tariffs.

--
Roland Perry

In message <uf6bl0$8a6h$1@dont-email.me>, at 11:15:44 on Fri, 29 Sep
2023, Tweed <usenet.tweed@gmail.com> remarked:
>>>>>>> Transport for London (TfL) – in partnership with Boldyn
>>>>>>>Networks – today confirmed that Euston station on the Charing
>>>>>>>Cross branch platforms has today become the latest place on the
>>>>>>>London Underground to go live with 4G and 5G mobile (mobile
>>>>>>>broadband) cover, which customers of EE, Vodafone, O2 and Three UK will benefit from.
>>>>>>
>>>>>> And customers of their MVNOs? eg Tesco mobile on O2.
>>>>>
>>>>> Only if it supports VoLTE (aka Voice over LTE, aka Voice over 4g). I use
>>>>> giffgaff, which doesn't.
>>>>
>>>> But presumably data still works?
>>>
>>> I was thinking of whether you might get a normal phone service. I don't
>>> know whether you'd get a data-only service. I can't see why not,
>>> technically.
>>
>> I make/receive about one voice call a week, so data-only would be
>> sufficient.
>>
>> Is there such thing as SMS over LTE, or is it a subset of VoLTE?
>
>I don’t think it needs VoLTE.

Without VoLTE, and with no classic coverage in tunnels, how *would* they
be sent/received. Or is the answer "they won't"?
--
Roland Perry

Roland Perry <roland@perry.uk> wrote:
> In message <uf6bl0$8a6h$1@dont-email.me>, at 11:15:44 on Fri, 29 Sep
> 2023, Tweed <usenet.tweed@gmail.com> remarked:
>>>>>>>> Transport for London (TfL) – in partnership with Boldyn
>>>>>>>> Networks – today confirmed that Euston station on the Charing
>>>>>>>> Cross branch platforms has today become the latest place on the
>>>>>>>> London Underground to go live with 4G and 5G mobile (mobile
>>>>>>>> broadband) cover, which customers of EE, Vodafone, O2 and Three
>>>>>>>> UK will benefit from.
>>>>>>>
>>>>>>> And customers of their MVNOs? eg Tesco mobile on O2.
>>>>>>
>>>>>> Only if it supports VoLTE (aka Voice over LTE, aka Voice over 4g). I use
>>>>>> giffgaff, which doesn't.
>>>>>
>>>>> But presumably data still works?
>>>>
>>>> I was thinking of whether you might get a normal phone service. I don't
>>>> know whether you'd get a data-only service. I can't see why not,
>>>> technically.
>>>
>>> I make/receive about one voice call a week, so data-only would be
>>> sufficient.
>>>
>>> Is there such thing as SMS over LTE, or is it a subset of VoLTE?
>>
>> I don’t think it needs VoLTE.
>
> Without VoLTE, and with no classic coverage in tunnels, how *would* they
> be sent/received. Or is the answer "they won't"?

Clearly you couldn’t be bothered to read the page that explains how
messaging is/can be implemented.

If you want definitive proof as to how it works on the tube you might have
to go to London and send yourself a text whilst on the tube LTE network. Or
write to Boldyn Networks and ask them.

In message <uf8m02$p96k$1@dont-email.me>, at 08:24:34 on Sat, 30 Sep
2023, Tweed <usenet.tweed@gmail.com> remarked:
>Roland Perry <roland@perry.uk> wrote:
>> In message <uf6bl0$8a6h$1@dont-email.me>, at 11:15:44 on Fri, 29 Sep
>> 2023, Tweed <usenet.tweed@gmail.com> remarked:
>>>>>>>>> Transport for London (TfL) – in partnership with Boldyn
>>>>>>>>> Networks – today confirmed that Euston station on the Charing
>>>>>>>>> Cross branch platforms has today become the latest place on the
>>>>>>>>> London Underground to go live with 4G and 5G mobile (mobile
>>>>>>>>> broadband) cover, which customers of EE, Vodafone, O2 and Three
>>>>>>>>> UK will benefit from.
>>>>>>>>
>>>>>>>> And customers of their MVNOs? eg Tesco mobile on O2.
>>>>>>>
>>>>>>> Only if it supports VoLTE (aka Voice over LTE, aka Voice over 4g). I use
>>>>>>> giffgaff, which doesn't.
>>>>>>
>>>>>> But presumably data still works?
>>>>>
>>>>> I was thinking of whether you might get a normal phone service. I don't
>>>>> know whether you'd get a data-only service. I can't see why not,
>>>>> technically.
>>>>
>>>> I make/receive about one voice call a week, so data-only would be
>>>> sufficient.
>>>>
>>>> Is there such thing as SMS over LTE, or is it a subset of VoLTE?
>>>
>>> I don’t think it needs VoLTE.
>>
>> Without VoLTE, and with no classic coverage in tunnels, how *would* they
>> be sent/received. Or is the answer "they won't"?
>
>Clearly you couldn’t be bothered to read the page that explains how
>messaging is/can be implemented.

I'm on a road trip abroad, and don't appreciate being told in effect "do
your own research". It sounds like *you* know which page that is, so the
least you could do is nominate it.

>If you want definitive proof as to how it works on the tube you might have
>to go to London and send yourself a text whilst on the tube LTE network.

Unfortunately any experiment like that is such a small sample (one
network, one phone, one version of Android, one SIM-package) that it's
hardly going to help give a big picture on the situation.

As it happens I never managed to get the (Virgin) free wifi on the tube
working, but have no idea which bit of the process of subscribing and
logging in wasn't working. I appeared to have all the correct
credentials required, but never saw any data flow.

>Or write to Boldyn Networks and ask them.

Or they could publish a plain English FAQ giving the long suffering
public a little bit more detail on what to expect.
--
Roland Perry

Roland Perry <roland@perry.uk> wrote:
> In message <uf8m02$p96k$1@dont-email.me>, at 08:24:34 on Sat, 30 Sep
> 2023, Tweed <usenet.tweed@gmail.com> remarked:
>> Roland Perry <roland@perry.uk> wrote:
>>> In message <uf6bl0$8a6h$1@dont-email.me>, at 11:15:44 on Fri, 29 Sep
>>> 2023, Tweed <usenet.tweed@gmail.com> remarked:
>>>>>>>>>> Transport for London (TfL) – in partnership with Boldyn
>>>>>>>>>> Networks – today confirmed that Euston station on the Charing
>>>>>>>>>> Cross branch platforms has today become the latest place on the
>>>>>>>>>> London Underground to go live with 4G and 5G mobile (mobile
>>>>>>>>>> broadband) cover, which customers of EE, Vodafone, O2 and Three
>>>>>>>>>> UK will benefit from.
>>>>>>>>>
>>>>>>>>> And customers of their MVNOs? eg Tesco mobile on O2.
>>>>>>>>
>>>>>>>> Only if it supports VoLTE (aka Voice over LTE, aka Voice over 4g). I use
>>>>>>>> giffgaff, which doesn't.
>>>>>>>
>>>>>>> But presumably data still works?
>>>>>>
>>>>>> I was thinking of whether you might get a normal phone service. I don't
>>>>>> know whether you'd get a data-only service. I can't see why not,
>>>>>> technically.
>>>>>
>>>>> I make/receive about one voice call a week, so data-only would be
>>>>> sufficient.
>>>>>
>>>>> Is there such thing as SMS over LTE, or is it a subset of VoLTE?
>>>>
>>>> I don’t think it needs VoLTE.
>>>
>>> Without VoLTE, and with no classic coverage in tunnels, how *would* they
>>> be sent/received. Or is the answer "they won't"?
>>
>> Clearly you couldn’t be bothered to read the page that explains how
>> messaging is/can be implemented.
>
> I'm on a road trip abroad, and don't appreciate being told in effect "do
> your own research". It sounds like *you* know which page that is, so the
> least you could do is nominate it.
I gave you a link to a page that explains the rather complicated way it is
all implemented. I knew you’d never be bothered to read it, hence my
warning it was too complicated to summarise it. So it’s not so much do your
own research as here’s a useful link.

According to Roland Perry <roland@perry.uk>:
>>>I don’t think it needs VoLTE. See here
>>>
>>>https://www.sharetechnote.com/html/Handbook_LTE_SMS.html
>>>
>>>I’m afraid you are going to have to read it yourself, it’s too involved to
>>>summarise.
>
>All I want is an answer to the situation I mention below.

I think the two minutes it takes to read that page and maybe one
that it links to would be well spent.

tl;dr It Depends.

--
Regards,
John Levine, johnl@taugh.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. https://jl.ly

In message <uf9s1n$133ff$1@dont-email.me>, at 19:13:59 on Sat, 30 Sep
2023, Tweed <usenet.tweed@gmail.com> remarked:
>Roland Perry <roland@perry.uk> wrote:
>> In message <uf8m02$p96k$1@dont-email.me>, at 08:24:34 on Sat, 30 Sep
>> 2023, Tweed <usenet.tweed@gmail.com> remarked:
>>> Roland Perry <roland@perry.uk> wrote:
>>>> In message <uf6bl0$8a6h$1@dont-email.me>, at 11:15:44 on Fri, 29 Sep
>>>> 2023, Tweed <usenet.tweed@gmail.com> remarked:
>>>>>>>>>>> Transport for London (TfL) – in partnership with Boldyn
>>>>>>>>>>> Networks – today confirmed that Euston station on the Charing
>>>>>>>>>>> Cross branch platforms has today become the latest place on the
>>>>>>>>>>> London Underground to go live with 4G and 5G mobile (mobile
>>>>>>>>>>> broadband) cover, which customers of EE, Vodafone, O2 and Three
>>>>>>>>>>> UK will benefit from.
>>>>>>>>>>
>>>>>>>>>> And customers of their MVNOs? eg Tesco mobile on O2.
>>>>>>>>>
>>>>>>>>> Only if it supports VoLTE (aka Voice over LTE, aka Voice over
>>>>>>>>>4g). I use giffgaff, which doesn't.
>>>>>>>>
>>>>>>>> But presumably data still works?
>>>>>>>
>>>>>>> I was thinking of whether you might get a normal phone service. I don't
>>>>>>> know whether you'd get a data-only service. I can't see why not,
>>>>>>> technically.
>>>>>>
>>>>>> I make/receive about one voice call a week, so data-only would be
>>>>>> sufficient.
>>>>>>
>>>>>> Is there such thing as SMS over LTE, or is it a subset of VoLTE?
>>>>>
>>>>> I don’t think it needs VoLTE.
>>>>
>>>> Without VoLTE, and with no classic coverage in tunnels, how *would* they
>>>> be sent/received. Or is the answer "they won't"?
>>>
>>> Clearly you couldn’t be bothered to read the page that explains how
>>> messaging is/can be implemented.
>>
>> I'm on a road trip abroad, and don't appreciate being told in effect "do
>> your own research". It sounds like *you* know which page that is, so the
>> least you could do is nominate it.

>I gave you a link to a page that explains the rather complicated way it is
>all implemented. I knew you’d never be bothered to read it, hence my
>warning it was too complicated to summarise it. So it’s not so much do your
>own research as here’s a useful link.

Having now found some connectivity to view that url, it's entirely "it
could/might be done like this" and absolutely nothing to provide a
shortlist of networks which actually *do* it like that.
--
Roland Perry