The pervasiveness of fibre in communications network infrastructure worldwide is a direct response to our insatiable demand for bandwidth. We want always-on, flawless broadband services, whether it is for watching videos, chatting with friends, or checking the weather (or our team’s score). 5G will add to this promise of broadband. Since 5G requires access to spectrum, which enables high throughput services and connections to dense, high capacity fibre optic networks, the importance of fibre to 5G cannot be overstated. A recent report by Deloitte Consulting shows that in the US alone, up to $150 billion will have to be invested in fibre over the next several years to adequately support broadband buildouts, rural connectivity and wireless deployments.

How fibre impacts 5G

The adoption of small cells is critical for achieving the network densification required for 5G coverage and capacity. Small cells strategically place radios closer to end users, thus improving the overall quality of experience (QoE) for mobile users. For the majority of service providers, the preferred transport method is fibre because it is scalable, secure and cost effective. Fibre is also important for 5G fronthaul, particularly for small cell deployment. It enables operators to centralise baseband resources and connect clusters of radio units (C-RAN architectures). This simplifies deployments by decreasing the equipment footprint and improving network efficiency through the centralised management of resources. With the use of fibre in fronthaul and access networks, operators can reduce the cost of backhaul, generating higher revenues per site and improving QoE.

Service assurance for 5G fibre

There are several factors that must be considered when testing fibre for 5G networks. To ensure proper operation, some tests should be performed during the installation and commissioning phases, including connector inspection and continuity tests, along with the characterisation of fronthaul and backhaul fibre links.

Operators also need to validate all components of the 5G network. System performance requires more than simply seeing a green light on a baseband unit or remote radio. Signal levels could be just marginal or on the threshold, incapable of surviving environmental impacts.

It is important to note that 5G networks have less tolerance for the overall light loss, making attenuation more of an issue than ever before. Dust, oils and water blocking gel are common forms of fibre connector end-face contamination. Simply placing dust caps on fibre connectors will not work in a 5G deployment since small particles can still migrate to the surface, and contamination can occur during building or staging.

Physical damage such as fibre breaks, strain, macrobends and elongation not only causes signal losses and communication failures, but also reduces the lifespan of the fibre cable. In fact, even 1 per cent strain exceeds the acceptable thresholds for cable performance. This issue is of particular importance in 5G networks as there has been an increase in the deployment of fibre-to-the-antenna sites. Therefore, active network monitoring is critical for service assurance as it enables the identification and repair of the damaged and stressed areas of fibre, reducing the mean time to repair and enhancing QoE.

Another key factor that must be considered in 5G fibre roll-outs is the skill set needed to deploy the networks. Fibre optic installers, contractors, project managers, technicians and engineers need to understand, correctly measure and record the performance of fibre infrastructure.

Competitive differentiators in 5G fibre

5G will create new revenue opportunities outside the traditional telecom sphere only if operators commit to provide the service guarantee and experience that these new enterprise verticals demand. Enterprise customers will demand 5G service performance that is backed by service-level agreements.

Since 5G networks are distributed across hybrid virtualised and physical infrastructure, testing and assurance can be complex. Mastering these networks requires operators to access empirical performance analysis data on how their networks are functioning. The ability to correlate and visualise that data is essential for assuring QoE.

Operators can create competitive differentiation in the market by applying service performance monitoring and assurance metrics to fibre-based networks. There is no doubt that business-critical 5G services will benefit from 5G technologies like Edge Cloud. However, in order to bring these profitable new business cases to life, it is vital for operators to implement accurate and proactive monitoring of applications, services and performance of their networks, with a strong focus on fibre health and resilience.

By Craig Black, Senior Director and General Manager, Fiber Optic Test, VIAVI Solutions