5G requires fibre-based infrastructure: Nokia

The road to 5G is paved with fibre, as the technology needed for the next stage in mobile connectivity will be a converged network based off both fixed-line and mobile infrastructure, Nokia has said.

"In order to have a 5G network, you need a cracking fixed-network line," said Mark Barnett, head of Mobile Networks Oceania for Nokia, speaking at a Communications Alliance 5G seminar in Sydney on Wednesday morning.

"You need a lot of fibre, you need really, really high-capacity fixed networks. So 5G is not just a wireless network. It's a wireless and a fixed network. It's network convergence."

Barnett described Nokia's vision for 5G architecture as cognitive and cloud-optimised network evolution (CONE), with security built into every layer of the technology.

The bottom layer of CONE involves converged access, he said, consisting of the 5G radio interface, as well as Wi-Fi, 4G, and fixed access. Importantly, this involves software-defined networking and network function virtualisation.

"An enabler for 5G is the software-defined networking, and this is one which we are actively discussing with pretty much all of our customers; they're transitioning their networks away from traditional transmission architectures to a software-defined networking," Barnett said.

"We're also virtualising all of the network elements of the network, and this starts with a network function virtualisation infrastructure ... this involves building generic x86 datacentres, and, in fact for 5G, moving to a distributed datacentre architecture.

"It means some pretty significant things about the transmission network that needs to be put in place to support this sort of architecture -- basically, a lot of fibre, a lot of bandwidth, if you want to centralise those functions. Centralised and distributed environments; we're actually distributing the core and centralising the radio, that's what's happening in this architecture revolution."

Stephen Coffey, Ericsson Mobile Broadband Engagement Practice Asia Pacific, said 5G will utilise and rely upon the 4G long-term evolution (LTE) infrastructure to leverage the existing spectrum allocation for future needs.

"5G is, as we see it, the combination of LTE as we have it today, and the evolution of LTE as we have it today, together with the new radio interface higher up in the frequency band -- 15GHz, 28GHz," Coffey said.

"As you start to go up in those frequency bands, they don't go so far. So that's why you really do need to rely very much on an underlying, evolved LTE network. And the LTE evolution is very much taking what we have today but carrier aggregating, for example, so we tape together some of the frequency bands we can use them as we're already doing today, so we can get double, triple, as much bandwidth."

According to Barnett, however, 5G is more than just a change in the radio interface.

"5G seems to come with it this notion that it's all about a new radio interface, with very, very wide bandwidth. The reality is that it's much more than that: 5G is a system of systems, and most of the work that we're doing today with our customers, and the real on-the-ground changes that we're making, and the deliverables are related to this system, the architecture of the network, the backhaul networks, the distributed datacentres, the virtualisation of core elements," Barnett said.

"These are the things that we're changing for 5G right away."

Barnett also spruiked the ability to use network slicing with 5G for more personalisation across networks. Using the slicing technology, a physical network can be segmented into several virtual mobile networks.

"One of the cool things that 5G enables is a capability called network slicing," he said.

"So by changing the end-to-end architecture, we can actually deliver to a different type of customer a dedicated network which provides them with all of the characteristics of the network that they require ... a dedicated network for dedicated purposes and programmable by the customer."

Ericsson itself demonstrated 5G network slicing technology in partnership with South Korea telecommunications giant SK Telecom in October last year, performing the demonstration at its R&D centre. Huawei also announced a trial of network slicing at Mobile World Congress (MWC) earlier this year.

Chris Althaus, CEO of the Australian Mobile Telecommunications Association (AMTA), also speaking at the Comms Alliance 5G seminar on Wednesday, said network slicing and the verticals involved are of interest to those in 5G discussions.

"Central to this [5G] is the verticals: We hear about the ability to slice a network, the ability to provide a very targeted and specific solution," Althaus said.

Verticals are being drawn into the development phase, leading to greater interaction than ever before between those developing, those deploying, and those who will use the technology, Althaus said.

Another of the drivers in Australia for the implementation of 5G is the investigation into the Universal Service Obligation (USO), which mandates Telstra as the fixed-line phone service provider of last resort and provides the telco with hundreds of millions of dollars each year for the installation and maintenance of fixed-line services.

"[The investigation] is a great opportunity to look at what is the Universal Service Obligation, and how does that develop, and how does that evolve over time, and what technologies and what sort of services are actually universal now and into the future?" Barnett said.

"Australia should recognise a forward-looking definition of the Universal Service Obligation, and take into account the sort of technology capabilities that are available now and in 2020 and in 2030, and that's kind of one of the things that's driving the discussion around 5G and the architectures."

Althaus also lauded the Australian government for its current review of radio spectrum regulation, labelling this one of the most important aspects in the development of 5G over the next four years.

Australian Minister for Communications Mitch Fifield in March announced the publication of the government's consultation paper concerning the overhaul of the legislation, licensing, and pricing of spectrum, saying the old legislation was so outdated as to be rendered "redundant".

"If we look at the network and the densification of networks including small cells ... and you look at the frequencies that we are going to have to deploy in terms of spectrum available, both these aspects are key now for the future of the 5G evolution," Althaus said on Wednesday.

"While a lot of [5G] is 2020 focused, I guess one of the key things for us is it's going to take a lot of effort and a lot of time to get the regulatory and policy settings right to support the vision ... and spectrum is most central to this."

According to Althaus, spectrum reform could save AU$160 million a year, and will improve the process.

"It will free up and in some cases increase the consultation burden on industry, but it will pave the way to a more efficient process in terms of deploying the sorts of infrastructure we need."

Spectrum frequency, geographic location, duration, whether a licence can be renewed, conditions where the ACMA would not renew a licence, terms for changing and revoking licences, payment mechanisms, and amounts to be charged will all be updated under the new legislation.

Another challenge in adopting 5G is in finding room for more base stations thanks to relying on spectrum with less depth, Coffey said.

"The spectrum itself means that the range will actually not go as far, so there's a high chance of having more base stations," he said.

"That's a challenge in itself, to get more base stations, particularly in the dense areas. That's where we're starting to look at innovative solutions of how you can actually deploy more cells in existing structures like poles for example, in bus shelters, in holes in the ground."

Both Barnett and Coffey said they are involved in discussions concerning 5G with operators throughout Australia and the wider Oceania region; Ericsson announced at MWC that it will trial run Telstra's 5G network during the 2018 Commonwealth Games in the Gold Coast.

Ericsson is expecting Category 16 devices to be able to support 1Gbps later this year or early next year via 4x4 MIMO.