21 August 2025
Despite widespread belief that dynamic spectrum access (DSA) is the future, European regulators (including the UK) are being cautious with its adoption. By contrast, the USA is taking a pioneering lead in this area with widespread adoption of CBRS and AFC in the 6GHz band. In this article we discuss several spectrum bands where Europe could take a leading role in adopting DSA – thereby ensuring in 20 years’ time, Europe is one of the makers of these technologies rather than being one of many takers.
What is DSA?
Dynamic access to spectrum means that the same frequencies can be used by different users (and for different uses) in the same geographic location at different times enabling more intensive use to be made of the spectrum. As shown below, an electronic database (a “DSA Server”) makes short-term spectrum assignments to many types of radio communications equipment, typically using a pre-defined priority order. DSA assignments can be made in seconds, compared with the existing long-term spectrum assignments which can take up to several months to obtain.
Why are European regulators so reluctant to introduce DSA?
Whilst many European spectrum managers agree that spectrum will increasingly be managed on a dynamic basis in the future, relatively few are willing to push to pioneer this technology. This partially results from failed adoption of DSA in spectrum used for television broadcast spectrum – so-called TV White Space (TVWS). TVWS technology suffered from restrictions on power levels that could be transmitted and the equipment ecosystem failed to develop. Additionally, as a new means of managing the spectrum, it is more complex and requires additional resources for regulatory and operational implementation. Many users of spectrum also prefer exclusive access and existing licensees view sharing of spectrum as a threat to them – often there is no incentive for them to share the spectrum.
Despite all these challenges, the USA has successfully introduced DSA in the CBRS bands (3550-3700MHz), where it is used for a wide range of private 4G and 5G networks, whilst protecting existing users of the band, including the US military. The USA has also introduced DSA in the 6GHz band to enable higher-power Wi-Fi use.
If the present pattern continues, Europe may come to regret not taking a leading role in DSA development, with all the benefits of these new technologies mainly going to innovators from the USA (and China?) – much as is currently the case in relation to the cloud technologies. However, we are still in the early stages of DSA, with much further development to be done, and so Europe still has the chance to be a pioneer – it does however require regulators to provide industry with the impetus to invest by introducing DSA as the assignment mechanism in several spectrum bands.
In which bands could DSA be introduced in Europe?
Learning from experiences with TVWS, we suggest that pioneer bands for introducing DSA should be those where existing equipment can be used but with the addition of a DSA client to obtain a frequency assignment from a DSA Server. Some examples of bands/use cases include:
- The 6GHz (5925-7125MHz) band – European countries have made the lower 500MHz of spectrum in this band available for unlicensed use (mainly Wi-Fi) but regulators are facing the challenging question of deciding how to divide the upper 700MHz in the band between priority use for Wi-Fi and priority use for high-power mobile base stations. Future demand for spectrum may be driven by devices/applications that today do not exist, and it is impossible to know whether the nature of use will be more indoors (requiring more spectrum for Wi-Fi) or primarily outdoors (requiring more spectrum for mobile) or both. Flexibility is therefore key – and a pragmatic solution may be to use DSA so that assignments can change in line with demand. DSA is well proven for use in Wi-Fi bands and is used in the CBRS band in the USA to provide frequency assignments to mobile base stations.
- The 3800-4200MHz band – This is being allocated for use for private 4G/5G networks in local areas including manufacturing sites, ports etc. A ‘static’ assignment approach would not support short-term access (e.g. for weekend festivals) or short-notice temporary uses (e.g. for TV breaking news content creation).
- Other spectrum bands allocated for public mobile use – Such spectrum is not always used by the mobile operators nationwide and other local users could co-exist with national mobile operators whilst always retaining priority access for mobile operators who have paid/are paying large amounts for the spectrum.
Aetha recently participated in a ‘spectrum sandbox’ for the UK government which investigated the use of dynamic spectrum access in spectrum bands allocated to mobile operators and the 3800-4200MHz band. This sandbox developed a protype DSA system, estimated the economic benefits of introducing dynamic assignment and developed a plan for regulatory implementation. Please find further details here.
Summary
Rather than being hesitant, Europe should embrace DSA and take a leading role in its development. Many innovations are still to be developed, for example improving interference prediction using AI to learn from real-world usage, which will all ultimately generate more economic value from the spectrum and reward countries and companies that are the pioneers.
