Institute for Telecommunication Sciences / Research Topics / Spectrum Management R&D / Interference Analysis and Mitigation

Interference Analysis and Mitigation

The Pew Research Center reported in early 2014 that 56% of U.S. adults now use a smartphone. To meet the exploding demand for wireless broadband for smart devices of all kinds, the President proposed an initiative to make 500 MHz of Federal and non-federal spectrum available for wireless broadband use by 2020. Since spectrum is a physically limited resource, this can only be done by opening bands to shared use or relocating incumbent users to underutilized, less desirable bands.

NTIA proposed sharing as a “fast track” solution in certain bands. Spectrum sharing proposals look to emerging technologies to enable interference-free sharing between commercial wireless broadband and incumbent Federal users. Smart wireless devices have such a rapid development cycle that it is feasible to imagine that by the time sharing has been codified, commercial devices entering a particular bandwidth will have the technology required to share gracefully with incumbents. However, many Federal incumbent devices that operate in the most desirable spectrum bands (like radar and satellite systems) have a refresh cycle of 50 years or more and are either difficult or impossible to update with new technologies due to their complexity or location.

“When necessary, repurposing of federal spectrum will be subject to conditions to ensure that there is no harmful interference with public safety needs or other critical public uses of the spectrum.”
The White House, Council of Economic Advisers, The Economic Benefits of New Spectrum for Wireless Broadband

While opening bands to shared use is the fastest way to accommodate more users, it is critical that safety-of-life systems used by the Federal Aviation Administration, the U.S. Coast Guard, the National Weather Service, and similar agencies be fully protected. At the same time, entrants into bands where such devices operate must be able to devise technology that can reliably operate around these systems in order to be able to fully exploit the bandwidth that is being made available to them. Effective spectrum sharing and spectrum reallocation can only be accomplished if both legacy and new services operating in the same or adjacent bands can be protected from interference so they can fulfill their missions. First, the interference potential must be understood and quantified. Then mitigation methods can be devised, tested, and standardized.

ITS is a recognized leader in radio frequency measurements, analyses, and simulations for interference prevention, diagnosis, and mitigation. Particular areas of expertise range from accurate measurement and characterization of emissions from transmitters of all kinds to complex simulation and modeling of proposed communications scenarios. From root cause analysis that traces experienced interference to its source, to developing complex mathematical models capable of driving multi-parameter simulations to prevent interference in systems under development, other Government agencies and private sector entities look to ITS for assistance to make sharing work. ITS performs interference research for other Government agencies via Interagency Agreements (IA) and for private entities via Cooperative Research and Development Agreements (CRADAs). These agreements provide benefits for both the Government and the private-sector partners. In addition to performing measurements and analyses on request, ITS engineers transfer knowledge to other agencies and the private sector through training in spectrum measurement, analysis, and modeling techniques developed over more than half a century of research.

ITS Interference Analysis and Mitigation Research Programs:

• Radar Program
• Analyses for Spectrum Sharing in Federal Bands
• Coast Guard Spectrum Reallocation Study
• Spectrum Sharing Innovation Test Bed Pilot Program