Spectrum sharing has been a topic of interest for decades, but recent developments are pushing it to the forefront of wireless innovation. With increasing demand for connectivity and limited spectrum availability, regulators and industry are exploring new ways to make spectrum work harder, without causing disruption to existing services.
Why does spectrum sharing matter now?
Policy makers in the UK have highlighted the importance of maximising spectrum use. The DSIT Spectrum Statement, published in April 2023, emphasised that innovation in wireless technologies, advanced spectrum management and enhanced sharing will help unlock new growth opportunities, ensuring spectrum is not a limiting factor for the UK’s economic and social potential.
Similarly, Ofcom’s Plan of Work 2025/26 notes that supporting innovation through timely spectrum availability and greater sharing is central to enabling wireless across the UK economy. Ofcom has also stated that it is exploring innovative sharing approaches through its spectrum sandbox initiative.
What has changed is the emphasis on making spectrum sharing work in practice. Historically, spectrum shortages were less of a concern. Today, growing performance and capacity demands mean regulators are struggling to identify clear, exclusively usable bands, pushing the industry to consider more innovative approaches.
Why is spectrum sharing increasingly seen as a viable solution?
Rather than offering exclusive access, spectrum sharing is now viewed as a realistic way to address the growing imbalance between spectrum demand and availability. However, sharing is not a simple solution. If designed or implemented without careful consideration, it has the potential to disrupt both incumbent users and new entrants.
Sharing can take many forms, depending on:
- The types of users involved
- Their relative priorities
- The technologies being used
- Whether sharing is geographic, time-based or simultaneous
Simultaneous use of the same spectrum by different services in the same geographical area remains particularly challenging.
How has technology made spectrum sharing more practical?
Advances in radio system intelligence have significantly improved the feasibility of sharing. Modern systems can now:
- Prevent mutual interference through integrated interference management mechanisms
- Identify, predict and mitigate interference using tools such as databases and, increasingly, AI-based techniques
Technologies like Wi-Fi already demonstrate dynamic channel switching in response to interference. These capabilities are now being explored in more complex and regulated sharing environments.
Why is sharing harder for systems with similar characteristics?
Sharing becomes more difficult when services have similar usage patterns and performance expectations, such as Wi-Fi and mobile connectivity. Users expect both to be available wherever they live and travel, which limits opportunities for spatial or temporal separation.
Despite this, the potential benefits are significant if workable solutions can be found. In many cases, success depends on balancing conflicting requirements, particularly the need to protect necessary services while still enabling innovation from new entrants.
Can the traditional approach be changed to accommodate the new users?
Standard practice has been for regulators to require new entrants to demonstrate that their systems would not cause harmful interference to existing services. However, new thinking on this approach could enable new users to use the same spectrum by making use of new advanced technical capabilities such as interference tolerance to support more users.
Findings from the Real Wireless sandbox project experiments showed that commercial and near-commercial systems often tolerate more interference than theoretical calculations suggest. While this tolerance varies case by case, it opens the door to more pragmatic sharing models.
Rather than relying solely on worst-case theoretical assumptions, real-world testing allows regulators and industry to:
- Assess interference likelihood by conducting field trials
- Understand how often interference is likely to occur
- Evaluate acceptable levels of risk over time
This highlights the importance of moving beyond purely theoretical models and focusing on practical experimentation in the field. Although measurements are not possible for all cases such as future technologies or systems operating in new bands, measurements conducted in other bands (if the band in question is not available) or using current technologies could provide more insights.
What are the opportunities for mobile and satellite sharing?
Sharing between IMT and satellite systems is of growing interest, particularly in the bands from 1 GHz to 2.6 GHz.
Addressing these cases will require practical interference management approaches rather than purely theoretical protection criteria.
Can spectrum be shared with defence systems?
Sharing with defence spectrum is possible but complex.
Studies examining IMT use in the 7 GHz range are part of WRC-27 preparations, but progress will remain tightly coupled to the information available about their use in the public domain.
Why is interference protection critical for space weather sensors?
Receive-only space weather sensors are one of the important agenda items for WRC-27. Ofcom has identified the protection of these systems as critical, particularly across frequency bands between 27.5 MHz and 614 MHz.
Interference measurement and characterisation studies are essential to understand real-world risks and develop effective mitigation strategies for these critical applications.
What does this mean for the future of spectrum sharing?
The future of spectrum sharing lies in collaboration, experimentation and the intelligent application of advanced technologies to ensure spectrum remains a driver, not a constraint, on connectivity and growth.
The Real Wireless-led Spectrum Sandbox Project explored spectrum-sharing opportunities in key frequency bands, specifically Mobile-Wi-Fi sharing in the upper 6 GHz band and private networks in the 3.8 to 4.2 GHz band. We validated the results of field trials and expanded into wider areas, refining propagation models based on our findings to bring the results closer to real-world conditions. These principles can be applied to other frequency bands to enhance the feasibility of spectrum sharing and boost confidence in real-world implementations.
