The realities of spectrum—Challenges, regulation, T&M and exploratory band searching

Consumer demand for faster-performing advanced services is driving a war in not only between the broadcast and broadband industries, but also between commercial providers and government users for space on the nation's airwaves.  The roll out of 4G LTE services is adding fuel to the fire, creating a nearly insatiable desire for scarcer spectrum.  In response to these challenges, providers are looking for options such as moving to new bands, which is opening up a whole new can of worms.

Spectrum as a Limited Natural Resource

Wireless devices, now ubiquitous in consumer, business, and military applications, all have one thing in common:  a need for radio frequency (RF) spectrum.  And, while spectrum is a renewable resource, that is no matter how it’s used today will still be available tomorrow, it is not unlimited.  Only so many transmitted signals can fit within this available spectrum “real estate.”  As demands for wireless devices and services continue to increase, how more of this real estate be made available to these new systems without causing disruption to existing users and systems is a worldwide problem since the first AM radio station was licensed in 1920.

To solve such problems as real estate limitations, and in an attempt to promote sharing of this limited natural resource, the spectrum has historically been subdivided into “bands,” where each band has been assigned to one or more specific uses such as television broadcasting, satellite uplinks and downlinks, air traffic control radar, and maritime communications to name a few.  These band assignments have been made and updated over the past 80+ years.  Because of that, some of the older users were some of the first to get spectrum—they were often given large sections of the best spectrum—the ocean-front property of the RF spectrum so to speak.

Once spectrum was assigned, wireless equipment manufacturers invested billions of dollars in building their systems to work in the bands allocated to these specific uses.  Simply evicting the squatters to move legacy users who may not really need all the spectrum they have to different parts of the spectrum (known as spectrum relocation) can require a very real, very large financial outlay—it is usually not just a matter of turning a knob to tune to a different frequency.

Regulatory Efforts and Challenges to Increasing Spectrum Availability

Spectrum band allocation has grown in complexity over the years to the point where it has become a patchwork (see image) designed to try to keep up with a changing wireless environment.  To further complicate cohesiveness, spectrum in the United States is regulated by two separate agencies that often have competing demands:  the Federal Communications Commission (FCC), which presides over commercial and private users, and the National Telecommunications and Information Administration (NTIA) for military and civilian government users.

In addition, it is important to note that radio waves do not stop at political borders, so coordination among and between countries must also be considered when national frequency allocations are made.  The International Telecommunications Union (ITU), an agency of the United Nations, is responsible for coordinating international use of the radio spectrum.  It has its own table of frequency allocations (actually, one for each of three regions) from which individual national tables are to be derived.  Every few years, national representatives meet at the World Radio Communication Conference to discuss changes to the ITU allocation tables and to negotiate specific exceptions for their countries.

This is all to say that spectrum relocation can be a very complex activity, fraught with both regulatory, financial and practical implications.  This means that just taking spectrum from legacy government users and re-purposing it for new services like LTE can be difficult, expensive, and time-consuming, sometimes taking as many as 10 to 20 years. There is another very important factor.  During  the beginning of current telecommunications revolution in the early 1990’s, some smart folks in the government realized that the spectrum resources that were given away by simply granting licenses as a public service (sometimes even via lottery) had real monetary value. 

When Congress understood that they could generate billions of dollars of revenue for the US Treasury, spectrum auctions were born.  Since its beginning in 1994, these auctions have generated over $60 billion and have become a model for the rest of the world.  But the “easy” bands that could be auctioned have now all been completed.  Verizon’s LTE service for example is in the newly-created (by FCC auction 73[1]) 700 MHz band; AT&T, Cricket and Metro PCS’s use of the AWS-1 band was made possible by auction 66[2].  

Once these spectrum auctions became established, however, Congress became accustomed to using the generated revenue to offset specific new federal spending.  At the same, the cellular industry continued to exert pressure to make more spectrum available for their use and the government wanted to make broadband services available to all.  So, in 2010 the White House issued a Presidential Memorandum directing the NTIA to collaborate with the FCC to make an additional 500 MHz of spectrum available for commercial wireless broadband technologies by 2020.

However, there were a number of restrictions on how this must be accomplished.  The President’s 2010 Spectrum Initiative also required  “… no loss of critical existing and planned Federal, State, local, and tribal government capabilities, the international implications, and the need for appropriate enforcement mechanisms and authorities.”[3]  Because the law requires that auction proceeds must exceed expected relocation costs, the bands selected for auction must carefully consider the real cost of moving out the existing government tenants.