Dark fibre is the really interesting bit of Ofcom's PIA decision

• BT must also give enterprise CSPs access to its ducts and poles
• Measures aimed at boosting FTTP rollout, supporting 5G
• PIA can halve the up-front deployment costs of so-called full fibre

Ofcom has made good on its proposal to force Openreach to provide dark fibre access (DFA) to rival operators, a proposal that the UK incumbent has previously resisted.

You may have missed it, because it was buried several paragraphs into a draft decision about extending duct and pole access to include enterprise CSPs as well as SME and consumer providers, making it cheaper and easier for them to deploy their own FTTP networks.

Under Ofcom's DFA plan, Openreach will be required to let rivals install their own kit at either end of its unlit fibre at exchanges where the incumbent faces no competition at all.

"Introducing dark fibre in only these areas would significantly reduce the cost for mobile and broadband operators to connect their networks, without undermining their incentives to lay new, competing fibre cables where it is economic to do so," explained Ofcom.

Nothing is set in stone yet; these are merely draft decisions. A final statement is due to be published next month and all being well the regulations will come into effect afterwards and will be in force until at least April 2021.

Historically, Openreach has baulked at the idea of providing DFA. It has argued in the past that letting other engineers meddle with its unlit fibre could lead to outages. It also claims that it threatens network investment; after all, why bother deploying your own fibre when you can regulated access to Openreach's?

This is Ofcom's second attempt to deliver mandatory DFA. The first time round, it fell afoul of the Competition Appeal Tribunal (CAT), which ruled that the watchdog erred in its definition of contemporary interface (CI) services (a.k.a. fibre-based Ethernet services), and that it had defined the rest of the UK telco market outside London as one homogeneous whole.

Crucially, the CAT didn't make any judgement about whether it is a good idea for rival telco engineers to go poking around in BT's exchanges, which may explain why BT is not loudly protesting Ofcom's new DFA decision – it may have used up all of its grounds of appeal.

That, or Openreach has come round to the idea of generating a bit of extra dark fibre revenue, and that any outages will reflect more negatively on the retail service provider responsible for the foul-up, and not the underlying infrastructure provider.

Meanwhile, Openreach has been much more receptive to physical infrastructure access (PIA). According to Ofcom, the likes of Virgin Media, TalkTalk and CityFibre between them are using around 12,000 telegraph poles and 2,500 km of underground duct. The regulators says PIA can halve the upfront cost of fibre deployment.

"Our measures are designed to support the UK’s digital future by providing investment certainty for continued competitive investment in fibre and 5G networks across the country," said Jonathan Oxley, director of Ofcom's competition group.