Where next for 5G fibre – piecemeal approaches don’t work

The UK must make the most out of its 4G assets and get into a much stronger position to lead on 5G.

But to do this, we need a plentiful supply of cheap, high-quality fibre for base station backhaul.


The dark fibre situation

So where are we on this now?

You’ll remember that just before the mandated launch of BT’s Dark Fibre product, they trounced Ofcom in the courts and got away with its earlier commitment – at least for the time being.

This prodded Ofcom to launch a new Dark Fibre consultation.

Analyst Matt Howett, innocuously described the new proposal as “slightly watered down.”


It certainly is ‘watered down’ – tarnished to such an extent that BT’s court victory is a really serious setback for Ofcom – and a very big win for BT.

The new Ofcom DFA proposals are truly inadequate – almost a waste of time.

But first here is the really bad news, some of our friends have been relaxed about Dark Fibre because they know that a different remedy – Passive Infrastructure Access (PIA) – is just around the corner.

But, don’t hold your breath.


Passive Infrastructure Access limitations

Ofcom says the new rules for PIA (coming in the Spring) will maintain the requirement for its principle use to be for mass market broadband.

What this means is firms that just want duct access for base station backhaul can’t have it – unless their main business is mass market broadband.

Worryingly, Ofcom is relying on PIA not being used for leased lines to underpin demand assumptions for the new Dark Fibre product.

We live in a strange world, don’t we?


BT Dark Fibre

Turning to the Dark Fibre detail; Ofcom proposes to force BT to launch dark fibre for the period up to 31st March 2019.

The rationale for this is not clear. It’s possible there may be a new review of the business connectivity market (BCMR) next year which may specify new all-embracing rules, beyond March 2019.

Even so, it’s not encouraging for those of us who need to make long term plans. Will we actually have a DFA product after March 2019?

What’s more, it’s limited to services at 1Gb/s or less.

The document is clear that BT may not have significant market power in services above 1Gb/s. And it proposes that BT contractually limit its customers use of dark fibre to 1Gb/s or less.

It appears this is ‘enforceable’ because BT can regularly visit your premises – to maintain the fibre – and ‘check’ if you are using 1Gb/s or 10Gb/s optical modems.

Well, isn’t that just great. What kind of maintenance is this?   


Next, the geographic scope definition in the document is close to being incomprehensible.

For example, it’s difficult to know if Bristol and Manchester central business districts are in – or out.  You’ll need to check the exchange list to be sure you can get this service – where you need it.

Because BT Dark Fibre is not going to be available everywhere.

And just for good measure, the length of dark fibre you can have is limited to 45km radial distance. Not by the capabilities of the technology – but evidently to protect against customers using DFA ‘for the wrong purpose.’

Whatever the ‘wrong purpose’ means?

This proviso may have been a restriction in the original DFA service – but the ‘wrong purpose’ rationale is a tad surprising.

So, what are these ‘wrong purposes?’


Using DFA for ‘the wrong purpose’

Well, BT Dark Fibre is not permitted for “Core Conveyance” in your networks, only Access.

In a world of ‘edge intelligence’ in mobile and enterprise networks – who can say, with any conviction, what is core – and what is access?

Think about this – a master base station controlling a cluster of local small cells in a city. Is it backhaul link Access or Core Conveyance?

You could argue it either way.

There are dangers in building new regulations on outmoded technical architectures.

The truth is Ofcom has twisted DFA into a very strange shape to ram it through the legal hole left by the competition and markets tribunal.

It may be a short-term tranquiliser – but it’s certainly not the dawning of the new age we need for 5G.


Dark Fibre was supposed to allow customers freedom to use it in any way they see fit – driving innovation and releasing value from monopoly assets.


2018 for 5G

2018 looks like a fascinating year for 5G – as interesting and important as this year. We can get much more stuff moving – but only if we grasp the opportunities hiding in plain sight – and remain frank, open and vigorous about what’s needed.