Model for Prediction of Digital Television Field Strengths Received at Individual Locations
Washington, D.C. 20554
May 19, 2011
Small Entity Compliance Guide
Model for Prediction of Digital Television Field Strengths Received at Individual
LocationsReport and Order
ET Docket No. 10-152
Released: November 23, 2010
This Guide is prepared in accordance with the requirements of Section 212 of the
Small Business Regulatory Enforcement Fairness Act of 1996. It is intended to help
small entities--small businesses, small organizations (non-profits), and small
governmental jurisdictions--comply with the new rules adopted in the above-
referenced FCC rulemaking docket(s). This Guide is not intended to replace the
rules and, therefore, final authority rests solely with the rules. Although we have
attempted to cover all parts of the rules that might be especially important to small
entities, the coverage may not be exhaustive. This Guide may, perhaps, not apply
in a particular situation based upon the circumstances, and the FCC retains the
discretion to adopt approaches on a case-by-case basis that may differ from this
Guide, where appropriate. Any decisions regarding a particular small entity will
be based on the statute and regulations.
In any civil or administrative action against a small entity for a violation of rules,
the content of the Small Entity Compliance Guide may be considered as evidence of
the reasonableness or appropriateness of proposed fines, penalties or damages.
Interested parties are free to file comments regarding this Guide and the
appropriateness of its application to a particular situation; the FCC will consider
whether the recommendations or interpretations in the Guide are appropriate in
that situation. The FCC may decide to revise this Guide without public notice to
reflect changes in the FCC's approach to implementing a rule, or to clarify or
update the text of the Guide. Direct your comments and recommendations, or calls
for further assistance, to the FCC's Consumer Center:
TTY: 1-888-TELL-FCC (1-888-835-5322)
Model for Prediction of Digital Television Field Strengths Received at Individual
Compliance Requirements1. Overview of the Rules and Predictive Model
The Satellite Television Extension and Localism Act of 2010 (STELA) extends the statutory
copyright license for satellite carriage of distant broadcast signals and related provisions in the
Communications Act, and also amends certain provisions of the Communications Act and the
Copyright Act. As part of the new statutory regime, the STELA requires the Commission to
prescribe by rule a predictive model for reliably and presumptively determining the ability of
individual locations, through the use of an antenna, to receive signals at the level of the signal
intensity standard for digital television stations in Section 73.622(e)(1) of [its rules], including to
account for the continuing operation of TV translator stations and low power television stations.
The signal intensity standard in Section 73.622(3)(1) of the rules specifies the threshold level of
signal strength at which digital television service is deemed to be available for reception off-the-air.
That is, when a signal's strength is above that level, service is considered available; when it is
below that level it is considered not available. The predictions from the model required by the
STELA are to be used in determining whether individual households or other satellite subscribers
are eligible to receive the signals of distant network-affiliated digital television stations, including
TV translator and low power television stations, from their satellite carrier. A satellite subscriber is
eligible to receive a distant network signal from its satellite service if the model predicts that no
signals of that network are receivable off-the-air in its local market area.
In the Report and Order in this proceeding, the Commission amended its rules to establish a model
for predicting the strength of digital television signals received at individual locations as required by
the STELA. The predictive model the Commission adopted, which is based on the existing model
for predicting the intensity of analog television signals at individual locations, allows such
determinations to be made in a timely and cost-effective manner for all parties involved, including
network TV stations, satellite carriers and satellite subscribers.
A copy of the Report and Order is available at:
2. General Information
The digital television signal strength predictive model uses an existing model for predicting radio
signal strengths at specific locations known as the "Individual Location Longley-Rice Model," or
"ILLR model." To make its predictions as accurate a possible, this model incorporates features to
account for terrain characteristics (such as hills), buildings, and land cover (such as forests), which
have a major effect on the strength of received signals. The model is implemented using a
computer software program that accesses databases describing terrain elevation data, descriptions of
the local environment of building structures and vegetation features, and the population of
transmitting facilities for which predictions are to be generated. The model assumes that a satellite
subscriber would use an outdoor antenna at 6 meters (20 feet) for one story structures and 9 meters
(30 feet) for structures taller than one story. There is no provision for prediction of signals using an
indoor antenna. The outdoor antenna is assumed to have the performance capabilities set forth in
the digital television planning factors described in a technical bulletin prepared by the
Commission's Office of Engineering and Technology (OET) titled "OET Bulletin No. 69, Longley-
Rice Methodology for Evaluating TV Coverage and Interference," February 2006. OET Bulletin
No. 69 is available on the Commission's website at
The new digital television version of the ILLR model incorporates parameters and features
appropriate for prediction of the signal strengths of digital television signals. This model is to be
used for predicting the signals of full power TV stations, low power TV stations (including Class A
stations) and TV translator stations. The specifications for the digital television ILLR model and
information on the computer program source code and how to use it are provided in a technical
bulletin prepared by the Commission's OET titled "FCC/OET Bulletin No. 73: The ILLR
Computer Program For Predicting Digital Television Signal Strengths." This bulletin is available
on the Commission's website at http://www.fcc.gov/oet/info/documents/bulletins/#73.
3. What are the local market areas of network television stations?
The Commission's rules define local market areas as the 210 "Designated Market Areas" identified
by the A.C. Nielsen Company. A satellite subscriber is eligible to receive the signal of a distant
(out of market) network station from its satellite service if none of the stations affiliated with that
network that are located in the subscriber's DMA are predicted to be receivable at the subscriber's
4. Are separate predictions needed in the case of stations that broadcast multiple programs
at the same time, i.e. provide multicast programming?
No. There is no need for multiple predictions from the digital ILLR model for the same station to
address work multicast program streams. The prediction of signal strength for a digital television
broadcast signal applies regardless of the content, including the presence of multicast program
streams. If a household is predicted to receive a station, then all of that station's program streams
will be received equally.
5. If a local station that could not be received at my location changes its transmitter so that
its signal can now be received there or the Commission revises the prediction model, will I
still be allowed to receive a distant network signal from my satellite service?
In cases where a location was predicted to be unserved by a local network station, the
Commission's rules allow households that are receiving a distant network signal to maintain their
eligibility to receive a distant network signal if either the station changes its signal coverage or the
Commission updates the digital ILLR model. This provision avoids disruption of the existing
services to which households have been accustomed to receiving. It applies only in cases where the
household already is receiving a distant signal from its satellite provider prior to a change in the
digital ILLR prediction model or in the coverage of the local station.
6. Where can I find documents about the model for prediction of digital television field
strengths received at individual locations and the rules for its use?
FCC order adopting the predictive model: Report and Order in ET Docket No. 10-152, FCC 10-
194, released November 23, 2010.
OET Bulletin No. 69:
OET Bulletin No. 73:
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