Link: 9 Insights Into Spectrum Management
Spectrum belongs to every country as a natural and renewable resource. It is limited because of the demand by so many different sectors of industry, commercial business, education/academia, research and government. For example, TV and radio broadcasters use their channels to entertain and inform. Many universities use frequencies for scientific research. Aviation uses spectrum for air-to-ground communications. Public safety uses frequencies for communications when responding to help citizens in trouble. Because of the limited amount of spectrum, governments manage the entire spectrum range for all sectors of industry, allocating segments as they need to, in the best interest of the country and as fair as possible for all users. There is a high demand for frequencies, often making it difficult to get spectrum when needed. Most of us believe that frequencies will always be made available for two-way radio systems, even if the spectrum takes a lot of time and justification to acquire. However, spectrum is becoming more limited and tougher to get.
See the full article here: Radio Resource Magazine: OnlyOnline.