How Aurora Telecom manages fibre networks and subsea cables

9 Jun 2023

James Freeman and Phelim Dolan. Image: Aurora Telecom

Aurora Telecom’s James Freeman and Phelim Dolan tell about the many opportunities and challenges presented by dark fibre and subsea cables.

Ever since the pandemic prompted more and more people to work from home, expanding and maintaining robust network connectivity has been top of the agenda for telecom operators.

And one of the ways in which telcos based in Ireland are expanding this critical infrastructure is through dark fibre, which is essentially a fibre-optic infrastructure on a linear basis. This unused optical fibre can be leased from carrier and enterprise service providers such as Aurora Telecom.

“In Dublin, that might be from a premises to a premises, or a data centre to a data centre, or a premises to a data centre, and regionally it might be from a city to a city,” Aurora general manager Sean O’Donnell told last year.

“We will provide the fibre-optic infrastructure in their comms room in one building and into the other comms room in the other building and it’s up to our customers then to put the equipment onto it and then they light the fibre by sending pulses of light down that dark fibre.”

More than a year later, Aurora continues to expand and maintain its sprawling dark fibre infrastructure across Ireland, but the task is not without its challenges.

Backhaul network

James Freeman, fibre design manager at Aurora, told in an interview recently that while dark fibre creates significant business opportunities in Ireland and strengthens it as an international tech hub, availability and security are still issues.

“Many challenges exist in terms of environmental impact studies, in terms of road open licenses, in terms of the demand in certain areas in rural areas in Ireland, especially where the network currently exists,” Freeman said.

To overcome some of these challenges, Freeman said Aurora has deployed this network adjacent to its parent company infrastructure.

“This allows for a more diverse, deeper and more secure network increasing our network availability. Aurora Telecoms network has been built in such a way that allows it to be a backhaul network.”

Other than dark fibre, subsea cables have also become a vital network for data travelling around the globe. These long cables lie on the ocean floor and send data as pulses of light inside thin strands of wires, or optical fibres, within the cable.

As of last year, there were four subsea cables connecting the island of Ireland to the US and eight linking the island to Britain. But they can be difficult to deploy and maintain, not to mention expensive.

“Submarine cables are an expensive deployment for the operators, so we make sure we have a robust backhaul in place,” Aurora network manager Phelim Dolan told

According to him, some the key performance indicators for operators is latency and network availability – and Aurora’s current national fibre network availability is at more than 99pc.

“In terms of latency, how we design and construct a network is also a massive consideration,” Dolan continued.

“We have maximum separation between our enclosures so on average four kilometres, but we can go less than that or greater than  that depending on access points or where we need to access the network.

“If you consider traffic coming from America is going to land, for example, in a cable landing station that needs to be backhauled from the west coast of Ireland to the east coast, the signal will never make that distance, so our operators require a co-location facility where they can access power and space and put in equipment that will take that signal to Dublin.”

Subsea cables are seminal to global data flow, with approximately 99pc of internet, voice and data traffic being carried over them.

“These cables also improve interconnectivity from continents from countries and so connecting the USA to Ireland, Ireland on to the UK and indeed onto mainland Europe,” Dolan explained.

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Vish Gain is a journalist with Silicon Republic