Two things led me to write this post. First, much of what’s written about 6G focuses on what 6G could be, but little arguing for why we need 6G! Second, 5G offers a very flexible architecture and a rich roadmap which will need many years to fully develop and use. These two reasons makes the question of why we need 6G thought provoking.
A brief backdrop
The primary objective of evolving wireless technologies is improving performance – specifically capacity. This started with voice capacity and evolved with time to add and scale data services. This evolution culminated in 5G with a flexible architecture optimized to meet different use cases and deployment scenarios.
From a connectivity performance perspective, cellular technology has almost reached the theoretical capacity limit set by communication theory. Successive generations improved spectral efficiency to reach close to the Shannon limit. Capacity in the low frequency bands is maxed out. Most of the innovation has shifted to progressively improve efficiency in the high spectrum bands. Architecturally, cellular networks are fully integrated with the Internet where mobile traffic accounts for over 50% of total Internet traffic.
Today, operators are in process of deploying 5G which is still largely untapped. Most of the deployments are for radio upgrades to inject broadband capacity in urban areas. Very few operators deployed a 5G core network. The market for enterprise services which promises operators revenue growth after maxing-out on the consumer broadband segment, is yet to develop. Operators will need to wait a few more years to see the RoI on 5G.
So, why we need 6G?
6G is a necessity regardless of when 5G achieves a positive RoI. In fact, 6G might happen sooner than anyone thinks! If spectrum is the oxygen on the wireless industry, technology generations are the drivetrain that powers the industry forward. Every segment of the ecosystem needs a new generation of technology:
- Service providers need a reason to upsell subscribers on new packages to lift revenues. Operators dread the capital expenditure for network buildouts. However, as in the case of 5G, operators could deploy a new technology incrementally to spread capex over a longer timeframe. The ability to incrementally build a new technology generation is new – it started with 5G. This also means that It does not matter what 6G is: operators will create something they call 6G for competitive reasons. We’ve already seen that with 5G where US operators rebranded elements of the 4G roadmap as 5G. In the future, it will be more difficult to differentiate generations of technologies; there will be more room manipulation by industry players.
- Vendors always led in the development and hyping of the next generation of technology. More specifically, it’s traditionally the losers in the present technology generation who lead hyping the next-generation. The winners want to milk their existing markets to the extent possible, but they get dragged by the losers into a race for the next generation. Why vendors need a new generation is obvious. However, the slow evolution from hardware-centric models to software-centric model will only make it easier to blur the boundaries between technology generations.
- Governments and regulators stand to win on multiple fronts. To start, a new generation of cellular technology requires new spectrum allocations*: that’s a source of revenue for many governments. Moreover, as broadband availability stand to boost anything from GDP to corn production, no government would want to stand against a new generation. But in the case of 6G, there’s a new and more important factor in play. Geopolitics and the decoupling of the US and China economies, especially that related to technology, is going to play a larger role in cellular technologies. This is not a new issue: we’ve seen the competition between Europe and the US in 2G and 3G technologies. The “5G race” mantra – a meaningless concept that only serves to feed the hype – and positioning on Open RAN provide a preview of what lies ahead.
Users: The stress test
Subscribers stand to gain from a better experience, efficiency and productivity. But users don’t want to pay more for connectivity. Users feel entitled to get larger bandwidth just as PC users expect faster processors and more memory to keep in step with more demanding software applications. Applications such as XR, autonomous vehicles and other advanced applications are maturing over time, but nothing guarantees that service providers will benefit from them. Could it be possible that operators will offer users some form of 5G in the future called 6G? The migration from 4G to 5G shows this is possible. Moreover, as boundaries between technology generations melt, it will be easier than ever to package elements of a current generation as the next generation.
6G will amplify confusion
It is fairly certain that future technologies will bring slow improvements in spectral efficiency, except in higher frequency bands where it’s difficult to realize a good RoI. Extending operation into higher frequencies will hit financial and practical barriers that are hard to overcome. As the incremental improvements become smaller, it will be harder to differentiate among technologies – at least on the basis of the speed of service. We’ve already seen this in 5G which has limited performance gain over LTE in low frequency bands. The value proposition of 5G focuses on enabling mid-band operation which most operators in the world are deploying as a capacity layer. mmWave is a secondary technology at this stage as it remains challenged by the laws of physics.
Consequently, there will be more room for ecosystem players to make up 6G definitions to their liking. This is useful to position as a leader and innovator. Operators would use 6G claims to prod subscribers to switch providers or plans, while keeping capital expenditure under control. This happened to a certain extent in previous technologies, but I expect 6G will amplify such traits.
Concluding thought: The threat of a bifurcated technology
Geopolitical tensions present one of the most serious threat to the future evolution of cellular technologies. Intellectual property battles are not new; but 6G is likely to bring more government intervention related to IPR. Could this threaten a bifurcation in future cellular technologies into a US/Europe camp and a China camp?
* At some point this would need to change, but maybe not just yet!