How will we know if early 5G deployments are successful?

Telecoms.com periodically invites third parties to share their views on the industry’s most pressing issues. In this piece telecoms industry consultant William Webb offers some tips on how to track the success of 5G rollouts.

The first 5G networks are just getting deployed now with emerging rivalry between the US and South Korea. Operators talk of the blazingly fast speeds that might be delivered, but while impressive, is that how we should judge success when it comes to rolling out this supposedly-revolutionary evolution in mobile network?

In practice, most operators are planning their early 5G deployments primarily to relieve congestion in their city-centre cells, rather than to deliver wide-reaching faster throughput. The combination of hundreds of MHz of new spectrum, often at 3.5GHz, and the claimed higher technical efficiency of 5G should provide a huge capacity increase in the cells where it is deployed. Of course, for this to work, there needs to be a large user base of 5G handsets as well otherwise the additional capacity will remain unused – which will be difficult in the short term as few models are available, and those primarily at a higher price point.

Cell site deployments will take time, and the penetration of 5G handsets will take some, perhaps a year or two until there is a significant number in use. With that in mind, it will likely be years before we can be sure that 5G is delivering better network – be that by capacity upgrade, or reliable access to the mythical 300 Mbps promised.

For 5G to have truly “arrived” – in the sense that it’s making a meaningful difference for operators and users, not just “arriving” on a billboard – two separate milestones will need to be achieved:

Given the limitations outlined above, it will likely be years until those goals are achieved. However, thanks to the early capex on spectrum, research, and cell site technology – not to mention the marketing hype — regulators, business leaders and investors will want some inkling of how the rollout is going long before 5G becomes the norm. So what might we look for? There are a number of indicative topics that watchers of the 5G rollout can track to establish early signs of success.

How successful has the deployment been of large, heavy massive MIMO antennas on existing city centre sites?

If the primary purpose of 5G will be to ease congestion in city centre locations, it stands to reason that the earliest investments will be on massive MIMO technology at existing city centre locations, potentially alongside investment in additional cell sites in the region. By using crowdsourced data, like that collated by Tutela, watchers can look at the proportion of cell sites that have 5G frequencies installed on them by operator, how this varies over time, and whether there are many missed sites in cities indicating deployment difficulties.

Will the beamforming be able to extend the range of the 3.5GHz frequencies such that 5G reaches to the edge of the existing cells?

One of the challenges of 5G will be ensuring that 5G signal can cover the same area per cell site as 4G. All else being equal, the propagation characteristics of 3.5 GHz mean that the same-strength signal from the same cell site will cover a much smaller area than the 1800 MHz equivalent; the hope is that using beamforming technology, the signal can be actively steered towards user equipment, improving the range and delivering an equivalent coverage to currently in-use LTE spectrum.

One way to monitor the range achieved on 5G would be using metrics such as the average timing advance in the cell as a proxy for cell radius. This will tell us if 5G range is matching that of some, or all, of the 4G frequency bands.

Will the promises of enhanced spectrum efficiency through beamforming be realised in practice?

Similarly, in areas where 5G and beamforming technology has been applied, it will also be important to assess whether the investment is actually driving additional efficiency as promised – or whether a new strategy is needed.

By using crowdsourced data, it will be possible to examine the amount of data delivered over 5G per MHz to see what spectrum efficiency might be achieved. This might need to await heavily loaded cells before we can be sure, but there might be early indications in places like major train stations.

Will enough users have 5G handsets or move to the 5G frequencies to use the additional capacity? For example, in-building users might find the 5G signal too weak and so stay on 4G.

One of the other core assumptions of 5G is that 5G-compatible devices will not only prove popular enough with consumers to take up a significant market share relatively quickly, but also that the usage of 5G frequencies will be effective as a way to reduce the load on existing frequencies, or whether in many cases they have to fall back onto 4G.

How the reality of 5G lives up to the hype remains to be seen. However, as the rollout takes shape it will be important to benchmark whether deployments are going to plan in a way that brings about observable differences to consumers’ experience of their network. We will be monitoring closely over the coming months and years to let you know the very latest on 5G deployments around the world.

Professor William Webb is CEO of the Weightless SIG, the standards body developing a new global M2M technology. He is also Director at Webb Search, an independent consultancy, where he acts as a consultant for companies including Tutela. Previously, he was a Director at UK regulator, Ofcom.