With 5G, We Plan for the Best but Must Test for the Worst

Things are getting real with the rollout of 5G networks, with greater dependence on connectivity likely to effect irreversible change on operator responsibilities. That's because while 5G delivers a substantial boost in network performance, its real benefits are tied to the enabler role it plays in the emerging connected world of the future. This role means network operators must test for worst-case scenarios to create more robust and dependable infrastructure than any preceding technology generation. Help is at hand, with the intriguingly named Digital Twin offering a viable and proven methodology underpinning unimpeachable quality assurance.

The challenge is that as 5G becomes a fundamental component in crucial life-and-death situations, redundancy, resilience, and availability have never been more important. Just consider steering multiple self-driving cars through a smart city intersection, with the network providing essential connectivity between all moving parts. This makes clear why network operators must approach network reliability, including digital defense, to protect human life. If the network is compromised, you're looking at a wreck.

Several additional factors further heighten the difficulty faced by network operators. 5G technology has an increased dependence on software for network virtualization and disaggregation. This could render mobile networks susceptible to previously 'air-gapped' cyberattacks and ushers network operators into a new paradigm in which improved service assurance and security measures become essential infrastructure components.

Test Cases Covered by Digital Twin

Furthermore, while network operators are generally very good at testing for what should happen, they aren't adept at testing for what shouldn't. For example, they've never tested a network for powering a city's physical infrastructure, or for keeping an automated vehicle on the road. Now, as 5G networks roll out, service assurance must cover physical danger, accidents, cyberattacks, survivability and real-world harm.

As we've seen, testing 5G networks is crucial to their success, both in terms of individual networks, as well as the success of 5G’s role in an ultra-connected future. However, what worked for a 2, 3 or 4G network will not work for 5G. Testing needs to change too.

For instance, previous generations off the network were deterministic leading to repeatable lab testing of well understood scenarios. That will not cut it for 5G, as the specific conditions and state of the network can't always be known, rendering traditional “sunny day” lab testing incomplete and not always practical.

Introducing the network Digital Twin

Now we get to the part you've all been waiting for. The network Digital Twin is a virtual representation of a real-world system or sub-systems serving as a realistic digital counterpart. The 'twin' emulates everything, from network functions to “sunny day” traffic mixes and the “rainy day” chaos of impairments and security attacks, providing a representative test bed where testers can run scenarios, evaluate integrations, cyberattacks, natural disasters, maintenance mishaps, and anything else.

The method is used for testing complex systems where reliability is crucial, including those in aeronautics, architecture, and manufacturing. Proven in these industries, it can work for 5G, too.

Because the network Digital Twin emulates real conditions at scale, it can create a model of the millions of devices and intense traffic of a 5G network, allowing for performance evaluation. Model 5G radio frequency channel ranges and propagations. Emulate base stations, fronthaul devices and the interactions between the core and the edge. Assess networking slicing (where parts of the network are "sliced" and virtualized, creating specific configurations for different use cases). It can even simulate GNSS satellite signals from multiple constellations under any condition.

Digital Twin for Test & Validation

Where the network Digital Twin really makes its mark is emulating conditions for evaluating chaos, what-if scenarios, and network security for specific circumstances. The self-driving cars and the smart city intersection powered by 5G? No problem. A smart 5G enabled factory? Punch it in. Farming at the edge with cellular Internet of Things sensors? It’s done. In fact, any behavior the 5G network can do, the network Digital Twin can be programmed to test and emulate.

Crucially, it can emulate impairments, so operators can evaluate what happens if their infrastructure fails or suffers from cyber-attacks. It can continuously assess the secure posture of a given network and preemptively identify vulnerabilities and risks, even incorporating continually updated real-world threat intelligence.

Network operators can create mitigation strategies for improved resilience through network configuration and architectural adjustments. A network Digital Twin can eventually become part of a continuous integration and continuous delivery environment, so operators can continually improve and refine their infrastructure. Furthermore, the Digital Twin can test devices and assets as soon as they come onto the network. This allows testing to go hand in hand with innovation and scale to match the ambitions of the network operator.

It's hard to overstate the profound obligations that come with 5G technology. It will fundamentally change what it means to be a network operator, bringing not only new frontiers of capability, but also new risks and responsibilities. As network operators seize these opportunities, they'll also require suitably rigorous test regimes.