FCC Proposes Increased Digital Power for FM stations

On August 1, 2023, the FCC released an Order and Notice of Proposed Rulemaking ("NPRM") seeking comment on proposed changes to its rules to give digital FM and Low Power FM stations more flexibility to increase digital sideband power levels. The item was released in response to two Petitions for Rulemaking that proposed rule changes to improve digital FM signal quality and minimize the effect of the digital FM station signal on adjacent channel FM transmissions. The NPRM seeks comment on the following two proposals:

1. Amending the Power Increase Methodology and Notification Procedures: the FCC proposes to amend the methodology used by digital FM stations to determine whether they are eligible to increase digital FM power up to -10 dBc, or 10% of the station's analog power and notification procedures for such increases in power.
   
   
   1. Methodology: the FCC proposes to modify the methodology a digital FM station must use to determine whether it is eligible to increase its power above -14 dBc. The new proposed methodology would allow more stations to increase power up to -10 dBc without submitting a contour analysis. Specifically, the FCC proposes the following updated table be used to determine maximum permissible FM Digital ERP:
      
      

      Proponent Analog F(50,10) Field Strength at First Adjacent Station's33 Analog 60 dBµ F(50,50) Contour (Symmetric Sideband Operation)	Maximum Permissible FM Digital ERP
      57.9 dBµ and above	-14 dBc
      56.5 dBµ to 57.8 dBµ	-13 dBc
      55.6 dBµ to 56.4 dBµ	-12 dBc
      54.1 dBµ to 55.5 dBµ	-11 dBc
      54.0 dBµ or less	-10 dBc

      
      
      1. The FCC seeks comment on this proposal and whether it will create an unacceptable risk of interference to adjacent-channel stations.
      2. The proposal would not affect the power level for previously authorized superpowered FM stations
   
   
   2. Notification: The FCC also proposes that such increases be permitted without the need for individual special authorization, but upon basic notification to the Commission via LMS utilizing the same procedures currently used to notify the Commission of digital operation up to -14 dBc.


2. Asymmetric Sidebands: the FCC proposes to grant blanket authorization to digital FM stations to originate digital transmissions at different power levels on the upper and lower digital sidebands without having to request experimental authorization. Any station would only need to notify the FCC of asymmetric sideband operations by filing notification in LMS.
   
   
   1. Methodology: The proposed new method for calculating per-sideband FM Digital ERP is represented in the following table:
      
      

      Proponent Analog F(50,10) Field Strength at First Adjacent Station's Analog 60 dBµ F(50,50) Contour (Asymmetric Sideband Operation)	Maximum Permissible FM Digital ERP
      54.9 dBµ and above	-14 dBc
      53.5 dBµ to 57.8 dBµ	-13 dBc
      52.6 dBµ to 56.4 dBµ	-12 dBc
      51.1 dBµ to 55.5 dBµ	-11 dBc
      51.0 dBµ or less	-10 dBc

      
      
      1. When operating asymmetrically (with one digital sideband having more power than the other) the Effective Radiated Power at each sideband must be adjusted so that the total sideband powers do not exceed the total power that would be authorized for that station operating in symmetric sideband mode.

Public Notice
Under the current system, symmetric digital sideband power changes are accomplished by notice to the staff, the staff takes no action on them, and they do not appear in the Commission's public notices of broadcast applications or broadcast actions. Symmetric digital operation at power levels between -14 dBc and -10 dBc currently require both notification and a showing that the contours generated do not overlap with the protected contours of adjacent channel FM stations, are confirmed by the staff, but not subject to public notice. The Commission seeks seek comment on whether it should require public notice for any of these changes and if so, what type of notice and whom should be notified.

If you have any questions would like any additional information, or are interested in submitting comments, please let us know.

Gregg and Dennis

This column is provided for general information purposes only and should not be relied upon as legal advice pertaining to any specific factual situation. Legal decisions should be made only after proper consultation with a legal professional of your choosing.