5G and fibre – where are we now and where are we heading?

The Promise Of 5G

The term 5G has entered into the mainstream vocabulary as mobile operators bring to bear the might of their marketing machines to catch the attention of the fashionable and technically savvy early adopters. But aside from the polished commercials, let’s remind ourselves of what 5G really means.

Yes, 5G is faster 4G, for sure. But 5G also means wider coverage, higher levels of network reliability and lower latency and the ability to connect billions of devices, most of which won’t be mobile handsets. It is only when all these attributes are combined that we can truly realise the full promise of IoT and the futuristic world of applications.

But isn’t there a disconnect here? 5G services have now been launched in most European countries, at least in the largest cities, and 5G Handsets are widely available. But we haven’t really seen that step change in applications which has been promised. So what’s happening?

It is important to make clear that the commercial launches of 5G to date are really the first stages of the wider deployment. The more revolutionary aspects of 5G capability will need higher frequency bands and since these signals are more fragile, it will need many more antennae than existing macrocell sites can support. Hence, we haven’t yet seen the scenario where lamp posts and other street furniture start to sprout new hardware which is needed to support the mobile technology of the future. But one thing is certain, that technology will need the bandwidth that only fibre can deliver.

Network Densification

One way to increase coverage/bandwidth capacity for a mobile network is to “densify” it by adding more sectors, meaning deploying more macrocells. This way, the number of subscribers connecting to a given cell and therefore sharing the available bandwidth is reduced, so that more bandwidth can be allocated to each subscriber per cell.

In countries where the density of cells prior 5G deployment is good, mobile operators will only have to add the new 5G radios to the existing sites. 5G technology will also operate at higher frequencies in the millimeter-wave band, as there is plenty of spectrum available allowing wider channel bandwidth, highest peak rates and a lot smaller form-factor antennas.

But a key factor is that every new wireless site needs both data and power, and provision of this connectivity is the biggest cost element in network densification. It is therefore inevitable that mobile operators will avoid this investment until the nature of the services provided over the 5G network demand it.

Optical Connectivity Challenges

It is widely accepted that the only way to deliver the densified Radio Access Network (RAN) capacity needed for 5G will be over fibre. This is a simple consequence of the amount of data which will need to be carried

over the network. A basic comparison of the differences in data rates for the transition from 3G to 5G is shown below.

But how does the 5G RAN application influence the optical cable and connectivity products used in the networks compared to other optical networks including FTTH?

Well, surprisingly little in terms of functionality of the end to end components, but the pursuit of improved reliability, flexibility and cost effectiveness is more pronounced.

3.1 Optical Cable

The cable pathways for 5G RAN deployments will be very similar to those used for traditional telecom fixed network deployments, i.e. mostly traditional duct and chamber routes or aerial routes on poles. So it follows that the advances in optical cable technology which have been exploited by the fixed network operators will be relevant to the mobile operators – who in many cases are evolving into fixed network operators anyway, and vice versa.

Of course, the fibre itself is the most critical element and Corning continue to lead the constant challenge to improve performance.

3.2 Optical Connectivity Components

The challenges of the 5G RAN are similar to any other external optical network in terms of environment and deployment methods, and it follows that much of the functionality of connectivity solutions developed for Optical Access Networks applies to 5G. However, there are some differences. For example, there will be greater demands placed on the Central Office connectivity to handle the increasingly diverse range of transmission equipment which will be deployed. This will be exacerbated by the advent of converged networks, more of which later. In order to meet these challenges there is a need to increase port density and improve usability and scalability and increase the ability to house for example WDM optical components.

Another aspect which differentiates 5G RAN infrastructures is the requirement to deliver power to the wireless devices. There is therefore a focus within R+D teams to develop hybrid solutions capable of incorporating fibre and power connectivity within the same package.

One key aspect that really unites all optical networks is the constant drive to reduce installed cost. That challenge has successfully been achieved in FTTH networks by deploying pre-connectorised solutions.

Finally, the reliability of optical networks is now almost taken for granted but due to the safety critical applications which will run over 5G networks, the bar will be raised. It is always therefore important to select materials which are fully compliant with the most rigorous ITU, IEC and Telcordia standards.

In summary, many of the challenges already encountered in optical outside plant networks will apply to converged networks, except with more focus on size, flexibility and reliability.

4. Network Convergence

The evolution of FTTH networks is in a really healthy stage of its lifecycle. The FTTH Council MENA Panorama 2019 revealed that the MENA region is represented by 3.46 million FTTH subscribers, led by UAE and followed by Saudi Arabia. UAE and Qatar are leaders in the region and also in the world with a very high adoption of fibre services. If we look at the overall figures for the MENA region as of September 2019, there has been a 18% YoY growth in FTTH/B subscribers in the region, and more than 6 million FTTH/B Homes Passed, which is a 19% YoY growth.

5G deployments are likely to be less fragmented across the different countries but the two technologies cannot be considered in isolation. In practical terms, connecting a 5G site is like connecting a house you didn’t expect to be there on an FTTH network. That’s why operators are designing extra capacity into their FTTH networks. But the art of network convergence really lies in predicting where that additional capacity will be needed. The fact that different countries are at different stages of their FTTH and RAN deployments adds another level of complexity.

5. Conclusion

It is impossible to predict how the capability of 5G technology will benefit us all in the future. The early 5G deployments are only scratching the surface of the full capability of 5G.There is significant investment being made now in large scale FTTH deployments throughout Europe and there is enormous potential to make that investment go further by realising the potential of FTTH / 5G Network Convergence. It is a critical time in the lifecycle of fibre deployment and correct decisions today will reward us long into the future.