The first pre-standard launches of 5G are due toward the end of 2018, writes Scott Sumner, the vice president of strategy at end-to-end network and application performance experts Accedian. However, standardised 5G will probably not arrive globally and at scale until 2021-2022. In the meantime, operators are upgrading their existing LTE networks to 4.5G.

On the journey to 5G, operators have reached a halfway point: LTE-Advanced Pro, also known as 4.5G. The main difference between 4G and 4.5G is an upgraded radio. 4.5G doesn’t need the full complexity of 5G’s multi-access edge computing (MEC) and virtualised RAN and core. Its radio upgrade enables better spectral efficiency, which in turn dramatically increases network speeds from what’s currently possible with 4G.

4.5G’s improvements in network speed and performance will delight subscribers who use their devices to consume rich media and other data-heavy apps and features. Its lower latency and higher network availability can also help operators explore and prepare their use cases for 5G –everything from connected cars to remote monitoring for healthcare, and industrial internet of things (IoT) applications like factory automation.

Getting 4.5G right isn’t easy
4.5G and 5G networks already have several features in common. Both feature upgraded RANs, and both benefit from improved spectral efficiency and increased bandwidth. But getting 4.5G right is not easy. Its increased speed and performance versus 4G – 10 times faster connectivity, 50% less latency – creates new and complex back-end challenges for operators.

The solution for operators is to add new backhaul links to the network – including between towers. But this also doubles the management complexity within the network. Operators must monitor the performance of more network links, more often.

4.5G and 5G mean extra complexity
The extra complexity of 4.5G increases exponentially with 5G. Where 4.5G and 5G diverge is 5G’s use of new spectrum bands, together with 5G’s increased use of network functions virtualisation (NFV), software-defined networking (SDN) and mobile edge computing (MEC). 5G needs these components to deliver ultra-low latency and network slicing, and also to support high availability apps like VoIP and HD video streaming, which depend on ultra-low latency and optimal network performance to work properly.

The extra complexity of both 4.5G and 5G creates other new challenges for operators—including around service assurance. Service assurance has long been an issue for operators, and the failure to properly identify, understand and fix user problems is the single biggest cause of subscriber churn.

To resolve these problems, operators have traditionally focused on the network’s performance to identify traffic glitches, bottlenecks and so on. They do so partly because of a pragmatic need to solve real network problems. But it’s also because operators are often unable to see beyond their own network and scrutinise the third-party apps and services that their subscribers are using – and potentially having problems with.

5G’s better user experience
For 5G specifically, much of its appeal stems from a better user experience as well as new applications and services. But 5G’s service layer for these apps and feature presents a completely new management challenge for operators. For example: large-scale IoT will load 5G networks with huge amounts of small, chatty sessions that can easily destabilise the wider network.

If operators are truly going to solve the user experience for, firstly, 4.5 and then 5G, they’ll need to expand and extend performance assurance along the entire chain of connectivity. What’s key is granular, real-time visibility and control across the full extent of the network – including its wireless and fibre backhaul components – and the apps and services running over the network as well.

The key to 4.5 and 5G service assurance? Granular network visibility
Without this visibility and control, it’s impossible for operators to create a tightly integrated layer of services and node connectivity that they can operate and manage efficiently, to ensure quality of experience (QoE) and quality of service (QoS).

This new kind of service assurance requires ultra-fast orchestration that can react within micro-seconds to dynamic changes in the network. It’s is more than a mere human can manage; therefore, artificial intelligence (AI) will play a major part. AI will self-learn from network key performance indicators (KPIs) to rapidly establish what constitutes normal or acceptable impairments, relative to impairments that are affecting end-user applications.

The network’s integrated nervous system
The sheer scale and dynamism of both 4.5G and 5G also means that existing hardware-based monitoring is simply not practical. For 4.5G and 5G to succeed, operators must put in place an integrated nervous system that lives within the network and which provides the sensory feedback needed to maintain performance and stability.

To ensure every application meets its required level of performance, operators must extend their visibility to the performance of services and infrastructure that are largely outside of their control. They can only do so with distributed, end-to-end network and application performance monitoring that runs at the multi-access edge and which is complemented by core visibility.