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A spectrum of challenges, a spectrum of opportunities

“Compared with past Gs, how concerned are you about spectrum challenges in 5G?”

This poll question was asked during a recent webinar1 on using (RF) spectrum2 in the era of 5G. The following graph depicts the answers of the webinar participants who replied to the question.

Graph - poll question on using (RF) spectrum
Results from a poll question asked during the EXFO and Heavy Reading webinar on (RF) spectrum efficiency (March 27, 2019)

According to this graph, there is considerable concern about spectrum challenges in 5G. Of course, the webinar participants who replied may only partially represent the mobile industry. But making the most of spectrum is definitely not a straightforward exercise. In practice, a multitude of challenges hinder the optimal use of this essential resource. On a high level, we could group spectrum challenges in two interrelated categories: cost, and complexity.


Licensed spectrum can be a considerable expense for mobile network operators. Although market conditions have changed since the UK 3G spectrum auction3 in 2000, the acquisition cost of a spectrum band license should not be ignored. And while unlicensed spectrum may be used too, the benefits of “exclusivity” make licensed spectrum the preferred option.

Spectrum is also costly to manage. For example, to deploy a more spectrally efficient technology such as 5G, substantial investment is needed. In some cases, investment includes site equipment that pushes cost upwards. Furthermore, sophisticated systems are required to monitor and optimize spectrum use, which increase CAPEX and OPEX.

This is inevitable as spectrum is inherently complex. To begin with, wireless signal propagation depends on factors such as the weather and the natural environment (for example, the impact of rain and trees has been a popular topic for 5G mmWave). Maximum capacity is also limited by the bandwidth available per band.
Interference–narrowband or broadband, constant or transient, RF or passive inter-modulation (PIM)–is another major concern. In addition, the dynamic nature of the radio environment makes matters worse. Even some network features or architectures (such as cloud RAN) for better efficiency are complex.

Finally, there is complexity in regulating spectrum, as seen in the 5G spectrum discussions. These have mainly covered the new (mmWave) bands for fixed wireless access (FWA). They have also focused on the regulation and worldwide harmonization of 5G bands.

Irrespective of challenges, spectrum is a critical foundation of mobile network performance and user experience and it must be used efficiently.

Opportunities and the 5G promise

The significance of spectrum has been increasing together with the importance of mobile networks. For example, mobile data demand has grown to 30 exabytes per month worldwide. In addition, mobile is a key enabler of broadband Internet access, which is frequently discussed as an emerging human right. Moreover, the ability to support a breadth of Internet of Things (IoT) use cases opens the door to new mobile-driven applications, including industry automation.

5G–the mobile network and industry transformation catalyst–promises to elevate mobile networks to a higher level. On top of enhanced user experience and service agility, 5G is expected to ingrain mobile in more verticals such as automotive, transport, logistics, utilities, manufacturing, media and entertainment, finance, and health.

5G also promises to bring optimal efficiency in the use of resources, including spectrum. Many hope that 5G will transform the way that spectrum is managed, from acquisition to deployment to optimization to re-farming. At the same time, we should be aware of the 5G paradox…

To learn more about the 5G paradox and (RF) spectrum challenges, read the EXFO white paper and watch the EXFO and Heavy Reading webinar on spectrum efficiency.

For a detailed discussion on spectrum–from its distinct challenges or the definition of efficiency to relevant solutions and lessons learned from diverse projects–please contact EXFO.

1 EXFO and Heavy Reading webinar entitled “Making the most of a limited resource: how to use spectrum more efficiently in the era of 5G.”

2 Referring to RF (radio frequency) spectrum as spectrum, for simplification reasons.

3 “UK mobile phone auction nets billions.” BBC website, April 27, 2000.