A clearer call for all
Techno Talk
Mark Nelson
Do you have a telephone line supplied by BT, Virgin Media or one of the other network providers?
If so, its underlying technology is about to change fundamentally, and the changeover might hit
you in the pocket.
I
t was half a century ago when
we in Britain began a comparable
technology turnaround. With wide
publicity, work began in 1967 to convert around 20 million appliances from
so-called town gas to natural gas piped
in from under the North Sea. From
start to finish, the conversion process
took around ten years to complete, and
modification of consumers’ appliances
was carried out entirely at the gas supplier’s expense.
The task facing Britain’s telephone
companies today is not identical.
However, the magnitude is similar
(there are around 33 million fixed-line
telephone subscriptions in the UK according to www.statista.com) but the
timescale is far shorter (about five years).
Our existing analogue telephone network will be replaced by voice over
internet protocol (VoIP) technology, in
which speech is transmitted as packets
of digital data in the same way as your
broadband service. Customers who do
not have broadband at the time of conversion will be provided with a modem
hub free of charge, since conventional
telephone exchanges will no longer
be used. Fortunately, your telephone
number will not change, and telephone
users should not notice any degradation
or difference other than clearer calls.
It’s happening already
BT and Virgin have already started their
conversion processes, which in some
(but not all) cases includes replacing
your existing copper telephone connection with an optical fibre. The rollout is
a piecemeal process and customers will
be informed when their line is due to be
converted. You cannot jump the queue,
as the only way that conversion can be
carried out economically is on an areaby-area and street-by-street basis. Just to
recap, the entire changeover is planned
to be completed by the end of 2025.
The existing analogue network is being
abandoned by all the UK’s telecomms
providers and you cannot have your old
copper lines reinstated. Conversion is
not a matter of choice either. If you are
10
wondering what the brave new world
of post-conversion will look like, take
a peep at https://bit.ly/pe-sep21-vm and
https://bit.ly/pe-sep21-bt (yes, I know
that other telephone providers exist,
but we don’t have space here to give
links to all their websites).
Probably the most striking difference
from the great gas conversion of the
Swinging Sixties is that whereas that
operation did not leave consumers out
of pocket, the same cannot be said for
all of today’s phone users. Taking just
one example, BT’s helpful footnote for
its new Digital Voice offering states, ‘If
you have special services, like a monitored burglar alarm or health pendant,
you’ll need to let your provider know
you’re moving over to Digital Voice.’
That is something of an understatement! When I had my security alarm
serviced last week, I asked the technician whether it would still work with
Digital Voice. He told me that my alarm
was totally incompatible and I would
have to have a brand-new system installed for £299 plus a substantially
higher monthly maintenance charge. I
foresee some frank and lively discussions ahead!
Legacy equipment
Will your existing cordless phone and
answering machine work on the new
system? Who knows?! Despite conflicting statements online, it appears that
in most cases your phones and gadgets
will operate if plugged directly into the
new hub that your telephone company
will provide. This means diverting your
extension wiring into the hub, assuming you have the DIY skills.
BT has a workaround for this. Its cunning plan is to give the latest version
of its Smart Hub 2 the ability to act as
a cordless telephone base station and
to sell mains-powered wireless adapters that make extension telephones and
answering machines connect wirelessly
with the hub. The product is called a
Digital Voice Adapter, item code 101488.
It plugs into the mains, and it registers
on the BT Smart Hub 2 in the same way
as the BT Digital Voice phone that you
receive when your line is converted to
digital. You then plug your third-party
DECT cordless base station or any other
phone into it (more details at: https://bit.
ly/pe-sep21-dva). Note that older phones
fitted with rotary dials will not work on
the new system unless you get hold of
a pulse-to-tone converter from a thirdparty manufacturer (these converters do
exist, and they work amazingly well).
Power problem
The new digital phone system comes
with a vulnerability that you need to be
aware of. One of the reassuring features
of today’s analogue telephone service is
its independence of power cuts. Unless
it’s a cordless handset, your existing telephone is powered not from the mains
but by substantial batteries located at
the telephone exchange. If the lights go
out at your place, you can still make
phone calls. This is not the case with
the new digital systems, which all depend on mains electricity to power the
hub and any other gadgets. If the power fails, you cannot call for the police,
ambulance or fire brigade. You cannot
rely on a mobile phone either, because
many smaller cellular base stations have
no battery backup and will go off air
immediately in a power cut. (All too
frequently, these towers remain off air
for several hours when the power fails.)
Battery backup for your hub and
phone system would mitigate this vulnerability, disregarding how ugly and
ungainly rechargeable batteries would
be. As of now, it is unclear whether
telephone companies will be forced
to provide backup batteries for their
digital telephone users by default, but
the current expectation is these will be
available only on request, at your cost,
and might work for only an hour. An
hour’s functionality will be a fat lot of
good when a tree severs an overhead
power line or when there are blizzards
and snowdrifts. Burglar alarms and
vulnerable folks’ emergency assistance
alarms will be unable to connect. Not
very encouraging, is it?
Practical Electronics | September | 2021
