Radio Spectrum Pollution: Facing the Challenge of a Threatened Resource

For a report summarizing the conference written by John Cook, Megan Coontz McAllister, and Laura Littman, Click Here.

Intensive use of radio frequencies by wireless systems is crucial to our economic and social well-being and to national defense and homeland security. Successful operation is essential for a wide variety of wireless applications ranging from simple keyless entry systems and garage door openers, to broadcasting networks, to Wi-Fi and cellular networks, to complex navigation systems like GPS and radar, to mobile radio systems relied upon by first responders. By analogy to other important economic inputs like coal, water and know-how, one can think of radio frequencies, also known as spectrum, as a resource.

The proliferation of wireless devices along with the increasing amount of frequency capacity consumed by each device (e.g. tablet computers used to upload or download video programming) has put intense pressure on the resource – a topic that has been addressed in many recent reports and at previous Silicon Flatirons events.

The good news is that, unlike other important natural resources such as oil, coal, or natural gas, the spectrum resource is not destroyed by use — it is infinitely renewable. However, like air and water, the spectrum resource can be polluted by interference from other radio sources. Since the quality of a radio service depends on the difference between the desired signal and the background noise, increased radio noise can reduce the total carrying capacity of the resource. When severe, the pollution manifests itself, for example, in the form of hissing or popping on radio channels, picture loss on television or other video feeds, interrupted wireless voice conversations, slow or intermittent internet connections and, in the extreme, degradation of communication and navigation systems that are vital to national security and homeland defense.

Depending upon the frequency range, radio noise can be produced by natural sources like lightning, by electrical machinery or other non-wireless devices such as automobile ignition systems and computer power supplies, and by unintended radiation from wireless systems. While there are regulations at the international and national level aimed at controlling manmade sources of interference, they are taking on more importance because of the increasing number of devices involved, the increasingly close proximity within which they must operate successfully, and the increasing importance of wireless services.

Since the level of aggregate radio noise from both natural and human sources decreases with increasing frequency, the intense interest in noise levels back in the days of short- and medium-wave radio has declined with the shift of critical wireless systems to higher frequencies. However, evidence is emerging that the radio noise floor is rising in higher-frequency bands that are especially important to both commercial and public safety applications.

The purpose of this conference is to bring together academics, policymakers, spectrum users and advocates to examine the extent of, and trends in, radio noise pollution and to suggest how the associated policies and regulations might need to be adjusted to reflect changes in radio noise levels. A unique feature of the conference will be an interdisciplinary panel directed at comparing and contrasting approaches used to control other forms of pollution (e.g., water and air) with those used in protecting the radio spectrum environment.

Other panels and a keynote address will be devoted to (1) how radio noise is characterized and measured, (2) what types and levels of noise pollution service providers and other users of the resource are actually observing in the field and the trends associated with those observations, and, (3) what tools are available in terms of both processes and advanced systems for enforcement, and where the associated priorities should be focused.

The formal portion of the conference will be preceded by a tutorial on spectrum pollution to better enable interested participants and attendees from other disciplines to more fully participate in the subsequent discussions.