In Need of New Windows of Opportunity for Database-driven Shared Spectrum Access

Arturas Medeisis

Vilnius Tech University, Lithuania

The issue

For an activity that enables such hotbeds of high-tech innovation as wireless broadband or satellite Earth exploration, the spectrum management itself remains strangely low-tech and largely entangled in century old ways of doing business. Granted, some practices have changed over last couple decades, such as auctions becoming near dominant mechanism for assigning commercial spectrum, or licenses allowing technological evolution within the given service, such as Land Mobile. Yet the spectrum access and use remain overall a strictly regulated process under close NRA control. It still involves extensive international studies and consensus building negotiations to decide on changing the utilisation of a particular band or allowing spectrum access for new technologies and applications. All this worked for many years and there is no reason, why this would not work for years to come. But clearly this way of doing business is not well suited for modern innovation and experimentation with new spectrum access techniques and new wireless business models.

Around a decade ago, there was some sense of high-tech innovation arriving to take spectrum management into the XXI century, with all the buzz of Cognitive Radio, “white spaces”, real-time dynamic auctions and so on and so forth. But the buzz has now all but faded and the only visible remaining practical example of all that hectic innovation efforts is the 3.5 GHz CBRS solution in the US. So why that innovation wave has produced so few sustainable results that really affect the way we manage spectrum? In large part this might be attributed to overhyped expectations meeting the harsh reality of fragmented markets and fledgling demand, which discredited the entire concept of Dynamic Spectrum Access (DSA) in early phase, resulting in regulators abandoning further support and rolling back on implementation efforts.

Lessons of stalled innovation efforts

A case in point could be the “TV White Spaces” concept in UHF bands, where the principal solution had been in hands reach, and was indeed already being implemented in a few pioneering countries. But the early Geolocation Database technology was still rudimentary, the markets’ focus was on evolving LTE at the time and the demand for TVWS did not materialise quickly enough to keep the momentum.

A similar story happened in Europe with Licensed Shared Access (LSA) initiative, which meant to allow mobile networks to tap into little used governmental spectrum in 2.3 GHz and possibly other bands. Around 2012-2014 there was a big push and broad support from regulatory establishment for that idea, a lot of hopes had been pinned on having ETSI standards developed, but once they were developed by 2017, it did not help to move the LSA from concept to implementation. It may be said that LSA emerged as a top-down concept recommended (as opposed to enforced) on European level by RSPG and CEPT. It remains unclear how much support there really was from industry and Mobile Network Operators (MNO), who initially indicated their tacit support, seeing LSA as means to obtain access to new trenches of mobile spectrum. But once the prospect of new exclusive 5G spectrum in 700 MHz and 3.5 GHz bands in Europe have materialised, followed by reasonably prompt issue of licences, the support for implementing LSA quickly dwindled across the board. It thus appears that having declared nominal readiness and tacit support for LSA, everyone – the industry and NRAs alike, were simply waiting for some champion first mover to demonstrate a successful deployment, be it a country or a strong European multi-national MNO. When this failed to happen, the LSA policy became broadly perceived as a failure. At that point it became very hard to revive it unilaterally in any one country, since establishing the complete ecosystem needed to achieve positive momentum and economies of scale became impossible for any single stakeholder.

Why we need more DSA opportunities

But with a view on growing success of CBRS innovation taking hold in the US market, it may be good time to re-consider the prospects of database-driven DSA solutions. The early implementations might have simply arrived too early, without mature connectivity and database technologies in place, and without properly aligned interests and coordinated efforts by all involved as well as potentially interested stakeholders.

The benefits of database-driven shared spectrum access are many. First of all, administratively, they may be seen simply as an automation of frequency assignment process. So as such their implementation does not require any changes to ITU Radio Regulations, national telecom laws or National Tables of Frequency Allocations. Very often, they might be enacted through secondary legislation such as NRA-issued rules for spectrum access and registration of transceivers. This means, that in principle, say, land mobile systems could have access by means of DSA to any band that is allocated to Land Mobile service in the ITU RR (and NTFAs), which are quite many. NRAs would just need to establish some meaningful interference-control conditions as part of DSA framework, and while that is not a trivial task, the previous developments and test runs with TVWS, CBRS, and LSA have all demonstrated that that should not be a problem in itself.

Secondly, the DSA platforms would be well poised to answer the growing demand for highly localised industrial/private mobile systems. They become increasingly popular as of recently, based on LTE and now 5G NR technological solutions as providing more robust solutions than Wi-Fi for industrial applications. For instance, Nokia has published estimates that worldwide there exist some 15 million venues/locations that may benefit of having a private local LTE/5G network or system (think of evolved “hot spot” access point). If each of those would get even a single micro base station/access point, all together that would rival the combined global number of MNO cell sites in terms of volume of radio hardware.

Similar recent predictions from Federated Wireless show that in the US alone, private cellular solutions using the CBRS may be worth some $3 billion in the next few years. While that figure, as many such forecasts, by itself is not meant to end up being anywhere near precise, the point is that the current market expectations are very high.

But having just one working solution like CBRS is not enough, not only because it is limited to one market, but also because it addresses just one band. We need to have multiple working DSA platforms in different bands as testing grounds to allow for spectrum access innovation to develop and flourish, in order to derive new knowledge and understanding of evolving sharing scenarios for 5G systems and beyond. And just like with CBRS, multiple DSA platforms, in different bands and markets, would allow a true testing of business models that may evolve thanks to managed shared spectrum access, as opposed to unmanaged best-effort shared spectrum access in “spectrum commons”.

Eventually and somewhat ironically, the DSA systems could even resurrect the notion of proverbial “Command and Control” regime as perhaps the most optimal way to manage spectrum. This might be indeed true, provided that those C&C decisions are taken not subjectively and arbitrarily by humans, but by centralised national databases in highly dynamic fashion, based on some clear technical criterions. The recent developments in nearly universal and cheap Internet connectivity, real time geo-location and mapping, coupled with proliferating cloud-based computing and database solutions, all make implementing such machine assisted spectrum access a viable reality.

Ultimately, different DSA systems, serving different bands and systems/users, could be combined into nation-wide Radio Environment Maps. Those would be useful both for spectrum users to guide their spectrum access decisions (locally and dynamically) and to NRAs to guide their understanding of what really happens in spectrum and any necessary interference resolution activities.

What needs to be done

The regulators have an important role to play in bringing forth such DSA platform innovations into modern spectrum management practices. The governments are critical in stimulating innovation and technological development through policy. This is especially so in the context of spectrum management, which relies on coordinated actions of many players on international and national layers. By organising broad co-evolutionary development efforts, the policymakers could provide meaningful leadership and guidance, bringing about the consolidation and networking effects. 

Previous research on innovation in the mobile industry had highlighted the remarkable interdependency and operational bonds of dominant players that results in forming of “strong networks”. This, in turn, results in the effect of “lock-in” to specific technological solutions and administrative as well as market relationships. In this light, the introduction of new spectrum access technology such as DSA would pose enormous challenges to implement a completely new technological paradigm of dynamic/opportunistic spectrum access, based on utilisation of novel spectrum geolocation databases. This would require significant reconfiguration of business relationships, which is never a straightforward process, and therefore needs some policy guidance. 

In particular, the deeper look at the circumstance of stalling of LSA innovation in Europe, suggests the following possible areas for developing supportive and remedial policy actions:

  • Recognising and addressing the ‘strong networking’ effects to break any current technological and business lock-ins: this could be done by expanding the design architecture and operational business scenarios of DSA frameworks to include non-MNO players, such as micro-operators and private enterprise mobile networks;
  • Propping DSA platforms to survive and evolve during the unavoidable initial hesitancy of the market players: this could be done by mandating DSA platforms as an obligatory solution for access to chosen spectrum band(s);
  • Developing new ‘soft institutional norms’ to further facilitate development of new players and emergence of new business models: this could be done by providing administrative incentives for new micro-operators such as zero pricing for access to spectrum managed by the DSA platform, providing targeted R&D funding to support market uptake and development of new business models;
  • It may be further suggested that NRAs need to take the central role (themselves or through appointed independent third party) of operating the DSA platforms in their countries as a trusted orchestrator. This would help building a system of trust from the get-go and laying solid foundations for new spectrum access paradigm.

These actionable items fall squarely into the traditional remit of the NRAs and some further coordinated guidance and harmonisation measures from regional organisations involved in spectrum management would be helpful and relevant as well.

By providing such support and opportunities to evolve for still fledgling DSA systems and similar shared spectrum access concepts and platforms, the regulators would build solid foundations for continued innovation in spectrum management. This would further invigorate the wireless communication markets, allow implementing and testing new technological solutions as well as new business models. Needless to say, that at the end we all – a growing global multitude of avid wireless consumers, would benefit.

Arturas Medeisis 

Vilnius Tech University, Lithuania

Arturas Medeisis holds PhD from Kaunas University of Technology, Lithuania. He has 27 years of experience in the field of radio spectrum management and development of radiocommunication networks and services. Throughout his career Arturas worked in various positions in national as well as international organisations – European Radiocommunications Office of CEPT and the Telecommunications Development Bureau of ITU, combined with industry and academia engagements. Presently he works as lead scientist at Cellular Expert company, which develops various cellular systems modelling software tools and provides associated professional services. Arturas also holds a position of Adjunct Professor at the VILNIUS TECH university, where he is teaching telecommunication technologies.

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