Finland is the latest country to jump on the 5G bandwagon, with its first fifth-generation test network being built in the northern city of Oulu.

The 5G Test Network (5GTN), led by VTT Technical Research Centre of Finland and University of Oulu in a consortium with industrial partners like Nokia, is scheduled to open in the latter half of the year. It will provide a test bed for 5G technologies, applications, and business models, with a research focus on network management, testing technology, and air interfaces.

"The idea is to trial different 5G concepts so we can gain the best possible understanding of their performance already before the [5G] standard is set," Kyösti Rautiola, research team leader at VTT, told ZDNet. "But the test network is also an application platform for building new early stage applications and to gain better understanding of the real-world benefits of 5G."

The network will consist of two parts: public and private.

The public network is an open test environment available to third parties. It will cover parts of the University of Oulu campus and also be offered to its circa 20,000-strong student body for real world results. The restricted private network, located inside VTT's premises, will be used by industrial partners.

Since 5G devices aren't yet available (5GTN expects to receive its first pre-commercial devices early next year), the network uses 4G LTE technology modified to meet the current 5G expectations. 5G remains a work in progress but the main criteria is widely accepted and includes minimum speeds of 1Gbps with sub-one millisecond latency and greater energy efficiency.

The test network will evolve into a full-scale 5G network as related technologies are developed and it will also be expanded to cover wider areas of Oulu.

Small cells and high frequencies

While several technologies are being considered for 5G networks, 5GTN's initial focus is on small cells and indoor networks. Small cells are smaller versions of the typical macro cell base stations (think the mobile equivalent of home wi-fi routers) and used to extend service coverage or to increase network capacity, especially in densely populated areas.

Both the public and restricted parts of the network in Oulu will use a combination of several small cells and one macro cell base station. The number of small cells will be increased as the network grows.

"The fastest way to increase network capacity is to divide, for example, the coverage area of one macro cell to tens or hundreds of small cells," explains Matti Latva-Aho, professor at the University of Oulu. "Small cells technologies, together with SDN, are the biggest changes in 5G network architecture."

SDN (software-defined networking) and NFV (network functions virtualisation) are low-cost and efficient ways to virtualise network infrastructure and make it easier to configure and manage. They work hand-in-hand with CN (gognitive network management), essentially smart network technology that automatically addresses and learns from data demands and problems experienced on the network.

"SDN, NFV techniques, and CN, which are already very close to 5G concepts, will be implemented during the first two years," Rautiola says. "Also major focuses early on are machine-type communication LTE-M [LTE optimised for machine-to-machine communications] and Internet of Things solutions."

But first the test network will be expanded to use another 5G concept: higher frequency bands, by early 2016. Moving from the low-frequency spectrum of 700MHz to 2.6GHz (a range used by most carriers today) to high spectrum bands above 6GHz could help to provide the large blocks of spectrum needed for 5G speeds.

Super high frequencies, also known as 'millimetre-wave technology', are already being tested by the likes of Nokia and Samsung to reach multi-gigabit speeds. In fact Nokia will supply some of the Oulu test equipment, notably the base stations, as it sees several usage scenarios for the network.

"[We can] get early insights into real-life performance e.g. by means of LTE-M live trial. Sharing early evaluation results with partners will help to iron out shortcomings and strengthen the technology for a successful commercial launch of 5G systems in 2020," Peter Merz, head of radio systems, technology, and innovation at Nokia Networks, said.

Business drive

Oulu is only one of the locations where 5G testing is gaining momentum. In Surrey, England, the 5G Innovation Centre 5GIC is scheduled to open in September, backed by £60m in funding. Meanwhile South Korea has invested a whopping $1.5bn on 5G development, and the EU's 5G development project '5G Infrastructure Public-Private Partnership' (5G-PPP) has so far received €700m in investment.

By contrast 5GTN's €7m funding for its first phase in 2015-2016 pales in comparison, but the research team emphasises that its focus is different.

"Our basis is that although there are plenty of technical challenges [in 5G], technology isn't our main driver," says University of Oulu's Latva-Aho. "Our aim is to trial entirely new business models and create an open test environment for companies to try out radical new concepts. In that sense we are challenging the current carrier led business models."

Part of this approach is to promote cooperation, not only on a Finnish level but globally - and here 5GTN is keen to work with 5G-PPP.

"We are starting early. 5G-PPP will be in the stage of building large-scale test networks in Europe only around 2017-2018, and we want to be strongly involved in that. In 2018, we will be much closer to a final 5G concept," Rautiola says.

While the first commercial applications of 5G are not expected until 2020, Rautiola believes it will bring major benefits for consumers and industry alike.

"Firstly, 5G will enable new Internet of Things applications and the management of large amounts of low-energy devices," explains Rautiola. "Secondly, a consistent service quality can be ensured for consumers while the use of wireless grows. Thirdly, for critical services, like infrastructure, network reliability and faster speeds are vital."

And here lies the problem: "These won't be possible without 5G infrastructure," he concludes.

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