Cop out: why has the PSTN switch-off ground to a halt?

The migration from the copper phone network in the UK faces another setback as BT has delayed the switch-off until 2027. What is driving the delay, and why is the move to fibre proving to be more complicated?

The much-tarnished copper landline network has received a stay of execution as BT announced this month that the migration to its digital telephone service, Digital Voice, and subsequent switch-off of the public switched telephone network (PSTN) will be delayed until the start of 2027.

PSTN accounts for around 41% of all landline connections, according to Ofcom’s 2023 Connected Nations report, but as the copper-based network reaches the end of its lifespan, and the parts and expertise to service it become scarce, the national phone network will eventually move to a fibre-based VoIP service, Digital Voice.

With the PSTN initially set for shutdown at the end of 2025, the decision to extend was made to give telcos and users more time to ready themselves for digital services. Given that 74% of customers are unaware of the switchover, this is likely to have been the right decision.

Digital Voice runs over fibre, requiring that compatible handsets be plugged into the router and a separate power supply. Traditional landline services, in contrast, are powered via a low-voltage feed directly from the exchange over the copper wire, so, provided that the exchange has power, users can always make calls on the PSTN.

However, unless equipped with a back-up power source, VoIP handsets won’t work in the event of a power cut, as seen in 2022 when major storms caused significant power outages across the country, leaving many who’d made the switch unable to contact emergency services.

Several telcos and fibre providers agreed to a government charter, committing to coming up with a shared definition of “vulnerable” customers, and not press forward with migration without confirmation that they have a working telecare device in place. Many of these telecare monitoring devices are landline-dependent, an issue highlighted by the deaths of two Virgin Media customers whose alarms had failed after their landlines were switched over (no evidence suggests that the switchover had any part in their deaths).

Copper networks are also responsible for a shadow network of additional supported living services, including lifts and building access systems, alarms and security systems. The bill for upgrading these would run into the millions, costing up to £70 million in London alone.

Keeping low-power mobile devices and sensors active is why many telcos are keeping their 2G networks running, but the costs to maintain and repair the increasingly obsolete copper network is increasingly unjustifiable as the number of users dwindles fast; the number of fixed lines – either PSTN or VoIP – declined by 950,000 during Q3 2023 alone.

Ofcom has thus said providers must provide a back-up solution to customers who rely on a landline, ensuring they can contact emergency services for a minimum of one hour in the event of a power outage, and that this be offered free of charge. BT plans to offer free battery back-up units, however these typically only last for one hour; last year, residents of Glasgow, London and Cardiff experienced power cuts averaging around three hours, while even the shortest average outages in Nottingham and Belfast lasted for one hour and 48 minutes.

BT has also urged councils to ensure that they share data to protect vulnerable users, but too many councils are reportedly failing to engage. Howard Watson, Chief Security and Networks Officer has warned that “more needs to be done and we need all local authorities and telecare providers to share with us the phone lines where they know there’s a telecare user.”

All this is a far cry from the heaps of help given out during the digital TV and radio switchover in the early 2010s. Promoted through a £200 million publicity campaign fronted by a friendly robot, the scheme provided free installation of equipment, a dedicated helpline, and 12 months of aftercare for over-75s or those in receipt of particular benefits.

The overall picture for PSTN switch-off across the world is mixed due to the different progress countries have made towards deploying fibre, and compared with its cousins on the continent, the UK is near the back of the pack, though is now catching up. France, Norway, Spain, Portugal, Japan and Australia are also in the process of shutting their copper networks down, while Germany, the Netherlands and Singapore have already switched off their copper networks.

Estonia has made the greatest strides, shutting down its copper network back in 2017 – an apt move for a country with one of the highest internet penetration rates in the world, though more easily accomplished when serving a population of only 1.3 million people.

If the UK’s new deadline is kept to, then the national phone network will be much better suited to the needs of modern connectivity services, and for most customers, the switch will be seamless. But the hands-off approach from the government to the switch-off, stressing that this is an industry-led initiative, has led to unnecessary widespread confusion for the most vulnerable customers who still rely on a landline for emergency assistance.

Update [19/08/2024]: The CEO of BT Business has this week written a letter to customers, warning them of the need to upgrade critical infrastructure to digital phone lines ahead of the PSTN switch-off.

Update [18/11/2024]: The Department for Science, Innovation and Technology has today published official guidance for CSPs on how to identify and support vulnerable customers during the PSTN switch-off.