The development of sharing and compatibility studies is a fundamental process in spectrum management and spectrum sharing, especially when introducing new technologies or allocating new frequency bands. These studies constitute the technical basis for assessing and demonstrating the feasibility of sharing the radioelectric spectrum, while also supporting a structured evaluation process to support regulatory decision-making at the World Radiocommunication Conference (WRC). They are essential to ensuring the harmonious coexistence of existing and emerging services without the risk of creating harmful interference. Sharing and compatibility studies provide the necessary assurance that the introduction of a new service will not compromise the operational performance of incumbent services.
Defining technical parameters and interference scenarios
Identifying the technical characteristics of the radio systems under study – both the newcomers (for instance, 5G base stations, IoT networks or non‑geostationary satellites) and the incumbent services they must share with (such as fixed links, aeronautical radars or Earth‑exploration satellites) – is the first step in any ITU-R technical study. Once those parameters are defined, engineers develop interference scenarios that assess co-frequency and adjacent-band operations under both worst-case and more typical conditions. Technical studies can be complex, as they may require intricate modelling of coordination distances, time-sharing mechanisms, or other interference mitigation techniques needed to avoid harmful interference. The study also considers common mitigation measures, such as beamforming, dynamic spectrum access, or defining guard bands that enable spectrum sharing. Depending on the intended service and the services already operating, aggregate interference analysis may be needed to analyse the impact of any potential new service deployments (e.g., thousands of base stations or satellites) on existing services.
From studies to regulatory frameworks
Ultimately, these intricate technical analyses culminate in the formulation of robust regulatory frameworks. The output of these studies directly informs the development of technical conditions and sharing rules that govern how different services can operate harmoniously within the same or adjacent frequency bands. This includes defining power limits, antenna characteristics, and operational parameters that minimise interference and optimise spectrum utilisation. The process ensures that the technical feasibility established in the studies is translated into practical and enforceable regulations, laying the groundwork for predictable and sustainable spectrum access for all stakeholders.
Results from compatibility studies shape the technical foundation for national and international policy and regulatory decisions. These technical documents are presented and debated during the Conference Preparatory Meeting (CPM) to guide the final methods that propose solutions to each agenda item. They help Member States and regional groups (CEPT, CITEL, APT, ASMG, ATU, and RCC) to develop informed positions and proposals for the WRC.
Timeline to CPM‑27 and key deadlines
The next World Radiocommunication Conference will be held from 18 October to 12 November 2027. Current efforts within the WRC-27 study cycle are centred on defining the technical parameters required to carry out the necessary studies. Throughout 2025, administrations will be submitting the initial outcomes of their technical analyses. However, 2026 will serve as the pivotal year for the presentation and in-depth discussion of these studies within the ITU-R working parties. According to the WRC-27 timeline, all technical studies are expected to be completed by early October 2026, in order to deliver conclusive results and propose methods to address each agenda item effectively.
The CPM is scheduled for April 2027. In the months leading up to it, administrations and other stakeholders will refine their proposals and weigh the findings of the completed technical studies. To participate effectively, each delegation must fully understand every agenda item and the studies that underpin it, so it can judge how the proposed methods might affect its national spectrum plan. Working Parties must file their draft CPM text by 23 October 2026.
Ensuring responsible spectrum sharing
Sharing and compatibility studies are not optional; they are foundational to guaranteeing the responsible evolution of the global spectrum landscape. For WRC-27, these studies will be pivotal in shaping future spectrum policy, fostering technological innovation, and maintaining equitable access across all services. Without them, decisions would be speculative and potentially harmful to incumbent services and users.
Access Partnership closely engages with the ITU throughout all stages of its four-year cycle and has extensive experience in supporting government ministries, regulators and private sector organisations engage in regulatory and technical matters within ITU and regional bodies. If your organisation is navigating the evolving technical and regulatory landscape in these areas, we’d be glad to connect and explore how we can support your goals. Please reach out to Xochitl Hernandez at [email protected] or PhD Josua Pena at [email protected].
