The document addresses the issue of intemational roaming within the framework of the Andean Communily (CAN), where for several years the intention has been announced to reduce the additional international roaming charges among member countries, without any measure being taken community in that sense so far. Therefore, at work a rationale or argument is made to take measures in the CAN to reduce and achieve the elimination of the cost ofintemational roaming, for the benefit of the citizens of the membcr countries and so that they can reach use the service when traveling between these countries at the cost of their local plans or rates. For this, the document is structured in five chapters that present: i) the fundamental concepts of international roaming and OECD recommendations on it; ii) Regulatory aspects and rates in commercial offerings in CAN countries; iii) the case of the European Union; iv) the rationale for the adoption of measures in the CAN; v) the recommendation of possible measures to be taken; and finally the conclusions are presented.

The work is an international review and analysis of administrative, economic, technical and regulatory strategies to promote the efficient use of spectrum, identify the best practices and make an assessment of the Colombian regulatory framework and a proposal to regulate this issue. The document develops the following questions: Definitions of Spectrum Utilization Factor (EUF) and Spectrum Use Efficiency (EUE). The document studies the international recommendations on the efficiency in the use of the spectrum. It conducts a benchmarking on regulations in the use of the spectrum in differents countries, identifying best practices. It analyzes the current regulations in Colombia and presents recommendations regarding the application of international best practices. A proposal was developed to calculate the efficiency in the use of the spectrum for mobile services, prioirtizing simplicity, as the research position developed in the previous chapters concludes the implementation barrier until now has been precisely the calculation difficulty and the amount of imformation required. Finally, the publication proposes an online consultation system for the efficiency calculation and a first development is published, including the information that should be made known to the public.