a spectrum that was limited had high economic value, which should be paid on the open market. Licenses are increasingly offered via spectrum auctions; however, this fails to consider non-commercial educational users (who are shut out of the process for economic reasons). Licensing is conducted by a broadcasting authority (a government agency) to manage the radio-frequency spectrum and implement public policy, such as that regarding the concentration of media ownership. In the U.S. the Federal Communications Commission (FCC) does not assign licenses to exclusive users, instead permitting qualified users to apply for a license. The Radio Act of 1927 established the regulatory premise that the spectrum belongs to the public, and licensees have no property rights to use it. Although the spectrum is licensed to bidders, its purchase does not entail ownership or rights but the privilege of using that portion of the spectrum. Process The process of obtaining a new broadcast license may be lengthy. A broadcast engineer first determines an available frequency, which may be unavailable in a crowded media market (such as a metropolitan area). If a frequency is available, an engineering study is submitted with an application to the broadcasting authority, to demonstrate that the licensee will not cause RF interference to existing stations. There is a limited term for the license, once acquired. According to the United States Government Printing Office in 1997, the term could exceed 8 years; however, this has been shortened to five years or less (depending on whether the FCC requires further evaluation). A construction permit is first issued, with the license receiving approval when the station certifies that the permit has been executed (after testing to ensure that all parameters are within allowable tolerances). Once a facility is built and operational, it may be allowed to operate under program test authority until the license is issued (or denied). Where a station is close to an international border, a license may also need to be approved by the foreign country's broadcasting authority for frequency coordination. This is done even if the border is outside of a station's predicted broadcast range, since radio propagation sometimes causes stations to be heard outside their service area. Existing stations apply for permits and license amendments when making changes to their facilities (such as relocation to another site, changing the radio antenna height, making changes to a directional antenna's radiation pattern, or when adding—or converting to—digital