The electromagnetic spectrum is divided into separate bands. The C-band is a portion of the spectrum that is useful for satellite and terrestrial broadcasts, including satellite communication, cellar networks, aviation, television, etc. Due to high demand for this limited resource, the U.S. Federal Communications Commission (FCC), alongside other countries' regulatory bodies, restrict broadcasting rights on the C-band to prevent interference.
The FCC has conducted “spectrum auctions” since 1994, whereby the highest bidders are granted more licenses to use portions of the spectrum. Recently, the FCC auctioned 100MHz of the C-band for 5G networks; AT&T spent $9 billion to win 40% (i.e., 40 MHz) of broadcasting licenses available in this auction, whereas other companies won a smaller fraction of the available licenses.
While some governments use spectrum auctions, other mechanisms to allocate spectrum licenses have also been used. For example, prior to 1994, the FCC often used “comparative hearings,” whereby the FCC would litigate the merits of each applicant, and assign spectrum licenses accordingly. Comparative hearings do not necessarily depend on the financial capital of the applicant; rather, government entities weigh the benefits and drawbacks of each application separately.