FCC seeks comment on ‘temperature’ model for RF interference

The FCC has adopted a Notice of Inquiry and a Notice of Proposed Rulemaking seeking comment on the use of a so-called “interference temperature” model when determining RF interference.

The “interference temperature” model accounts for the cumulative radio frequency energy from transmissions and sets a maximum cap on their aggregate level as opposed to the current approach that manages interference by limiting the transmit power of individual devices.

The Notice of Proposed Rulemaking is seeking comment on technical rules to set up procedures for a limited use of the interference temperature model in the 6525-6700 MHz and portions of the 12.75-13.25 GHz bands. The new procedures would be used to govern unlicensed devices operating in these bands that are currently used for satellite uplinking and fixed point-to-point microwave transmission.

Additionally, the Notice of Proposed Rulemaking is soliciting comments about whether such unlicensed operation in these bands will impact existing services.

“The introduction of a new ‘interference temperature’ model has the potential to tremendously improve radio spectrum management,” FCC Chairman Michael Powell said in a written statement on the Commission’s Web site.

“Rather than assess interference based solely on transmitter operations, the interference temperature model introduced in the Commission’s Spectrum Policy Task Force Report takes into account the cumulative effects of all undesired radio frequency energy. The marketplace demands for spectrum require that we explore new ways to use this resource more efficiently,” Powell’s statement said.

For his part, Commissioner Michael Copps expressed the hope that those responding to the notice would provide insight into the appropriate methodology for determining interference temperature. “While the interference temperature metric may be a good new way to measure interference, we do not have an adequate way to determine what the right interference temperature is for a given band,” he said in a statement on the Commission’s Web site.

“The only tools we have for this job are the ill-fitting and ill-defined ‘interference’ and “harmful interference” concepts. The inappropriateness and inadequacy of these concepts for the job of prospectively setting interference temperature will make this new metric very hard to use predictably and non-arbitrarily in the real world.”

For more information, please visit: http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-03-289A1.doc.

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