Institute for Telecommunication Sciences
the research laboratory of the National Telecommunications and Information Administration

Institute for Telecommunication Sciences / Programs / Spectrum Monitoring

Spectrum Monitoring

“The NTIA shall design and conduct a pilot program to monitor spectrum usage in real time in selected communities throughout the country to determine whether a comprehensive monitoring program could disclose opportunities for more efficient spectrum access, including via sharing.” (The White House, Presidential Memorandum: “Expanding America’s Leadership in Wireless Communications,” June 14, 2013.)

Optimizing Use of Spectrum Resources in Real Time

The growth and stability of wireless communications depends on real-time awareness of the radio frequency (RF) environment (generated through spectrum monitoring) and coordination of diverse communication services (spectrum management). Spectrum monitoring is long-term, continuous measurement of the RF environment from multiple sensors, providing real-time information about the use of radio frequencies across broad areas and enabling observation of historical trends and events. Broadly, it involves three components:

  1. Operating hardware that is capable of sensing radio signals
  2. Transmitting data about radio signals from the sensors to a centralized data repository using networking infrastructure
  3. Applying data analytics and visualization techniques to characterize the sources and strengths of radio signals, and to identify potential conflicts among them

Data generated through spectrum monitoring is used by spectrum managers to enforce spectrum use rules and frequency assignments.

Spectrum monitoring is also essential to optimizing the use of spectrum resources, now and in the future. New devices and technologies make new demands on the finite radio spectrum (e.g., smart home devices, self-driving cars).  Modern, dynamic spectrum management allows communications systems to use different frequencies at different times, or to share frequencies with other systems, depending on real-time spectrum availability within the ever-changing RF environment.


The purpose of the NTIA Spectrum Monitoring (specmon) program is to provide spectrum managers with more effective monitoring and advanced data visualization, enabling them to access information on spectrum use at a level of detail that was previously unattainable. Examples of such information include:

  • Actual spectrum use compared with assignment and license information
  • Occupancy statistics for different frequency bands, e.g., monitoring 3.5 GHz CBRS band
  • Spectrum maps for visualizing spectrum use and signal strength
  • Potential interference events identified with a specified level of confidence
  • Spectrum efficiency data (used to compare usage before and after rule changes)
  • Statistics on interference sources
  • Longitudinal studies on background noise levels


We also aim to establish community and breakdown silos. Goals are to establish standards (e.g., IEEE 802.22.3 SCOS standard), build community and break down silos through cooperative agreements (see Boulder Wireless Test Bed), and collaborate via open-source code development. Code repositories released to the public include:

  • gr-ltetrigger: set of utilities for sensing LTE
  • sigmf-ns-scos: specification that defines the controls and data format used within the Spectrum Characterization and Occupancy Sensing (SCOS) system
  • scos-sensor: platform for operating an RF sensor over a network
  • scos-manager (planned release Oct 1, 2018): server application to enable distributed sensing

Related Publications

[1] D. Anderson, “A Cost-Efficient, Field-Ready Sensor to Detect and Decode LTE FDD Downlink at Low Signal Levels,” GNU Radio Conference 2016, Boulder, CO, Oct. 28, 2016.
[2] J. Wepman, B. Bedford, H. Ottke, M. Cotton, “RF Sensors for Spectrum Monitoring Applications: Fundamentals and RF Performance Test Plan,” NTIA Technical Report TR-15-519, August 2015.
[3] M. Cotton, M. Souryal, J. Wepman, M. Ranganathan, J. Kub, S. Engelking, Y. Lo, H. Ottke, R. Kaiser, and D. Anderson, “An Overview of the NTIA/NIST Spectrum Monitoring Pilot Program,” International Workshop on Smart Spectrum at IEEE WCNC 2015, New Orleans, LA, March 9–12, 2015.
[4] M. Cotton and R. Dalke, “Spectrum Occupancy Measurements of the 3550–3650 MHz Maritime Radar Band Near San Diego, CA,” NTIA TR-14-500, Jan. 2014.

For more information about this program, contact Michael G. Cotton.