Because spectrum is such a scarce resource, almost every usable chunk of airwaves in the United States is accounted for and occupied by either federal or private users.

The federal government has worked to consolidate its spectrum holdings in recent years, auctioning off the 1710-1755 megahertz band in 2006 to a host of wireless carriers and planning for next year’s auction, which will include the 2155-2180 MHz band.

The 1755-1780 band is considered particularly desirable for wireless carriers because it can be paired with the 2155-2180 MHz band; most communications networks use one band to send messages and another to receive them, making the combined bands far more valuable.

The 1755-1780 band is also adjacent to the 1710-1755 MHz band and others used by cellular networks, and it is used for similar purposes in other countries. That means devices running on the band can be programmed to roam internationally on the same frequency for lower cost.

But the 1755-1850 MHz band is already allocated to 19 federal agencies for a multitude of uses, including transmissions from wireless cameras, microphones and other law enforcement surveillance tools; satellite dishes used to control military satellites; a fixed microwave system used by the Federal Aviation Administration; Defense Department tactical radios; air combat training systems; small drones used for surveillance; and a host of other military uses. Some of those networks may be easier to shift, while others would require new equipment or the replacement of costly satellites.

Further complicating any transition to private use is the government’s lack of granular insight into how the bandwidth is used. While the National Telecommunications and Information Administration maintains a high-level database of what agencies are authorized to operate in the various bands of spectrum, it lacks insight into how often or where those networks are used, making it difficult to understand the exact needs of the federal users.

The NTIA has already begun the hard work of determining exactly who must be moved, and what it would take. Whether that process will move fast enough to satisfy Congress is anyone’s guess.