5G test action moves to the core

Test company says research into network slicing driving "huge demand" for core emulation.

Test providers have been hard at work proving out 5G New Radio as vendors and operators target an accelerated rollout schedule. That work continues, but it is being joined by an increased focus on testing the core network as it evolves to support network slice configurations for enterprise use cases.

Stephen Douglas, Solutions & Technical Strategy Lead for Spirent, said the company is seeing “massive increased demands” for its 5G core network emulation technology. Spirent claims to be the first to have a 5G core network emulator and it can also model evolutions of the 4G core towards 5G, Douglas said.

These sorts of investigations are an “interesting indicator”,  according to Douglas, because they demonstrate the realisation that getting a 5G radio out early doesn’t really add too much commercial benefit to operators unless they can bring in the core and start enabling new services

This increase in demand is coming from Spirent’s traditional customer base and from research institutes that are researching network slicing use cases and industry-targeted use cases around 5G. “The big interest is in exploring what types of network slice will be relevant and the relationship between network slicing and network distribution,” Douglas said.

He added that these included questions such as, “If you are slicing the core, do you also need to distribute the user plane to edge locations, or signalling to this location, and does that change in lifetime of the slice. If a slice is targeted at moving vehicles, does latency become more or less of a challenge?”

Researchers are also interested in testing whether a slice could potentially act as a private network, replacing the dedicated networks that enterprises are more used to deploying within factories and campuses. That involves testing how resilient and robust that slice could be, and also how secure.

Operators thought they would use legacy OSS but now realise that will not be good enough

Security relates to another key area that Douglas says has been relatively unconsidered in the rush to deploy 5G NR – service assurance.

“Operators thought they would use legacy OSS but now realise that will not be good enough – especially as they bring in the new core. They need a new approach to service assurance.” Douglas said this included Spirent’s active automated testing solution, where test agents deployed as micro-services synthetically inject traffic to test SLAs or validate a new service or capacity turn-up.

“As the network architecture itself becomes more virtualised, what’s interesting is that a lot of customers have not thought through all the use cases that service assurance can provide for them.”

Douglas outlined four key areas, the first being turn-up testing that produces a “network birth certificate” outlining a minimum network condition to meet a service requirement. The second aspect is for more active monitoring against meeting minimum SLA requirements. Third is the need for change management as new software changes are introduced in a more continuous basis in the network. Finally, there has been a realisation that as there are more software updates and as distributed edge locations come online, the security risk increases. Having a mixture of test agents and emulation means the test system can emulate an attack to monitor if networks are robust enough from a security perspective.