Perhaps the most important key issue is whether the United States should internationalize the SPS. ... This study identifies the problems in obtaining international agreements on geostationary orbit availability, microwave frequency allocations and microwave frequency standards for satellites transmitting solar power. ... A review of [ITU] related instruments indicates that while the 'first come, first served' principle regarding the use of geostationary orbit has remained basically unaltered from a strictly legal point of view, the key issue will be how to translate that the ITU calls the 'efficient and economic use' and 'equitable access' into more specific legal and technical principles and rules relating to the geostationary orbit for what the Outer Space Treaty calls the "benefit and interests" of all countries.