SK and DT trial federated slicing, but will MNOs control multinational 5G?

SK Telecom, Deutsche Telekom and Ericsson have jointly built and demonstrated the first intercontinental 5G trial network, showing off a roaming particular application of the much-vaunted technology of slicing – which allows the network to be segmented into slices, on-demand, for individual services as defined by an enterprise or service provider.

This demo applied the virtualized technique to international roaming, making the two operators’ network slices available in one another’s footprint so that roaming end users would have the exact same experience in South Korea and in Germany. It was based on Ericsson’s new 5G Core, which uses SDN/NFV techniques to enable slicing and other capabilities (see lead article).

The demo is an interesting one, since roaming is always a thorny issue with any new network generation, and becomes more challenging – technically and commercially – as  more services and user experiences need to be supported. But while appearing to address some of the issues of delivering consistent experience without the user having to be passed back to the home network all the time, it raises further ones – particularly the need for operators to cooperate in ways which go beyond current roaming deals, and which may open the way for vendors to seize the upper hand in the international mobile value chain.

The three-way demo was hosted at DT’s corporate R&D center in Bonn, Germany and SK Telecom’s 5G testbed at Yeongjongdo in Korea. It centered on an industrial maintenance use case involving an engineer communicating with support colleagues while roaming abroad, using augmented reality. The scenario used local breakout and edge computing to reduce latency, boost throughput and make the overall experience the same as at home, the participants said.

In network slicing, rather than all services using the same network, each service can run in a slice which provides an optimized environment for that particular activity. In what the triallists call ‘federated slicing’, this is extended across borders. Instead of a service being delivered over one international network – enabled by interconnection and commercial roaming arrangements between operators – slices can be established in partner’s networks abroad to replicate the experience at home.

“5G is not just a faster network. 5G will provide extreme user experience anywhere and any time, even when the user roams across different operators globally,” said Alex Jinsung Choi, CTO at SK Telecom, in a statement. “Federated network slicing will enable seamless platform sharing amongst operators at a global scale for continuous and guaranteed user experience.”

As in any type of roaming, the barriers are often not technical but commercial. In their statement, the three companies emphasized that a prerequisite for federated network slicing is a cooperation model, in which operators open up their networks to host partner services and recreate slices.

Their agreements will be complex – the partners said: “These agreements should cover aspects such as: network slice availability at the access layer (cellular, fixed), availability in the core network and the connection to customer application servers. The hosting of edge cloud resources by the visited network enables the execution of special business functions that demand high throughput and low latency, close to the customer in the visited network.”

That may open an opportunity for a cloud network platform provider, such as a tier one vendor, to provide a multinational managed service, enabling interconnection and connectivity deals between operators in different country from a central hub, and taking over the role of assigning and managing slices.

This is an example of the way 5G could squeeze the MNO’s role in the value chain and allow a cloud provider – whether a vendor or a new entrant like Google – to become the spider in the middle of the web. Similar issues, in a nearer term scenario, were raised earlier this month when Nokia announced its WING managed service platform for international IoT connectivity.

Nokia will be the central point for connectivity agreements with operators in different countries, providing enterprise and vertical customers with a seamless cross-border network. While this saves a lot of time and hassle for the enterprises or the participating operators, it also places the most valuable role in delivering vertical market services – including those in slices – in Nokia’s hands, potentially relegating its own MNO customers to be invisible bitpipes and even setting itself up in competition with them.

The same conflicts or overlaps of interest will be even more difficult to resolve in the unmapped waters of cross-border 5G network slicing, as the mobile market – especially the enterprise and vertical aspect of it – moves to a distributed cloud model, and becomes far more like the rest of the cloud services industry, which is dominated by a few giants which hardly notice national borders.