Interview Most people are unaware of the huge infrastructure challenge the UK is about to undergo as 15 million phone lines are switched off.

Openreach is aiming to punt its traditional public switched telephone network (PSTN) onto voice over IP (VoIP) by 2025 and withdraw its Wholesale Line Rental (WLR) products, which are reliant on the PSTN. The potential for disruption is huge.

For example, businesses are still mostly on copper lines and can't afford for them to go down during the working day so the switchover will have to happen at night. There are also many vulnerable people who use telecare devices and alarms to call for help, which also run on the PSTN.

James Lilley, head of copper & service products at Openreach, noted that the company doesn't necessarily know where all those special services are and whether the devices would be compatible with the new VoIP service. That is why it is engaging with industry now ahead of its first trials.

Since it first announced the plans last year, around a million people have naturally migrated off the PSTN, but the rest is going to involve a huge industry push, he said.

"It's about to get quite real with a lot of this stuff," he said, likening the project's scale to the switch from analogue to digital TV in 2007. However, that involved millions in government funding, whereas this project is industry-led.

As Openreach doesn't deal with customers directly, it's reliant on its 600+ communication providers (CPs) to get the message across and ideally sign customers up voluntarily ahead of a forced migration by 2025.

"We've got a period between now and early November, where we are putting all the detail into the proposals for CPs, with a working group on 6 November. That will mark the formal start of making it happen," Lilley said.

"We are really trying to get the message out there.. we've made good progress but we're not there yet, as we're still coming across [people in the industry] who are hearing this for the first time."

Trial by VoIP

Part of its preparations involve a trial in Mildenhall, Suffolk, to switch off the analogue lines. That will begin on 1 December, with the stop date for selling WLR products set at May 2021 and the trial closure December 2022.

The town was chosen because it is a "typical exchange area" with a range of CPs offering Openreach services to businesses and consumers. But unlike Salisbury, where the copper lines are being switched off as part of a huge upgrade to fibre-to-the-premises, in Mildenhall consumers will still be on copper VoIP products.

For the WLR withdrawal, Openreach is launching a set of "Single Order Products". These include SOGEA (Single Order GEA) – fibre to the cabinet, but without the voice service running over the copper; SOGfast (Single Order G.fast) – a G.fast service without the voice element; and SOTAP (Single Order Transition Product) – a copper product that will provide a data path for those without access to fibre.

However, with talk of shutting off all copper by 2027, there is the potential for even further disruption to consumers. Some areas could have all their phones lines switched off by 2025, only to have those copper VoIP lines ripped out two years later as part of the FTTP upgrade.

Doubling up

Lilley agreed this scenario is "unavoidable to some degree". He added: "The years we really need to focus on are 2023-25, they are the key years that we don't potentially do double migrations." He said as Openreach's FTTP plans become clearer, it will be working with communication providers to try to avoid that happening.

Clearly this is a complicated programme. In Germany back in 2018, Deutsche Telekom announced a two-year delay to the completion of its flagship Europe-wide All-IP Migration scheme to 2020. Persuading business-to-business clients to migrate appeared to be one of the main reasons for the delay in its PSTN replacement initiative.

Given the scale of the project, is it wise to have 2025 as an immovable date?

"That is what the trials are about, so if we can spot all those challenges early on, we can do something about them," Lilley said. "We may get close to 2025 and critical national infrastructure services haven't been able to move for whatever reason, and clearly on a case-by-case basis we'd have to review how we supported those customers. But certainly 2025 is the end date." ®