[Federal Register Volume 78, Number 32 (Friday, February 15, 2013)]
[Proposed Rules]
[Pages 11129-11132]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-03486]


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FEDERAL COMMUNICATIONS COMMISSION

47 CFR Parts 73

[ET Docket No. 13-26 and GN 12-268; DA 13-138]


Office of Engineering and Technology Seeks Comment on Updated 
OET-69 Software

AGENCY: Federal Communications Commission.

ACTION: Proposed rule.

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SUMMARY: The FCC's Office of Engineering and Technology (OET) announced 
the release of new software to perform interference analyses using the 
methodology described in its Bulletin No. 69 (OET-69). This software, 
called TVStudy, provides analysis of coverage and interference of full-
service digital and Class A television stations. The Commission plans 
to use this new software in connection with the proposed broadcast 
television spectrum incentive auction (incentive auction). OET seeks 
comment on the software generally, as well as the identification of any 
errors, unexpected behaviors, or anomalous results produced in running 
the software. In addition, OET solicits comment on the implementation 
of various analytical elements in the software that are not 
specifically addressed in OET-69.

DATES: Comments must be filed on or before March 21, 2013 and reply 
comments must be filed on or before April 5, 2013.

FOR FURTHER INFORMATION CONTACT: Robert Weller, Office of Engineering 
and Technology, (202) 418-7397, email: [email protected], TTY (202) 
418-2989.

ADDRESSES: You may submit comments, identified by ET Docket No. 13-26 
and GN Docket No. 12-268, by any of the following methods:
     Federal Communications Commission's Web Site: http://fjallfoss.fcc.gov/ecfs2/. Follow the instructions for submitting 
comments.
     Mail: Robert Weller, Office of Engineering and Technology, 
Room 7-A134, Federal Communications Commission, 445 12th SW., 
Washington, DC 20554.
     People with Disabilities: Contact the FCC to request 
reasonable accommodations (accessible format documents, sign language 
interpreters, CART, etc.) by email: [email protected] or phone: 202-418-
0530 or TTY: 202-418-0432.
    For detailed instructions for submitting comments and additional 
information on the public Notice, see the SUPPLEMENTARY INFORMATION 
section of this document.

SUPPLEMENTARY INFORMATION: This is a summary of the Public Notice ET 
Docket No. 13-26 and GN Docket No. 12-268, DA 13-138 released February 
4, 2013. The full text of this document is available for inspection and 
copying during normal business hours in the FCC Reference Center (Room 
CY-A257), 445 12th Street SW., Washington, DC 20554. The complete text 
of this document also may be purchased from the Commission's copy 
contractor, Best Copy and Printing, Inc., 445 12th Street SW., Room, 
CY-B402, Washington, DC

[[Page 11130]]

20554. The full text may also be downloaded at: www.fcc.gov.
    Pursuant to sections 1.415 and 1.419 of the Commission's rules, 47 
CFR 1.415, 1.419, interested parties may file comments and reply 
comments on or before the dates indicated on the first page of this 
document. Comments may be filed using the Commission's Electronic 
Comment Filing System (ECFS). See Electronic Filing of Documents in 
Rulemaking Proceedings, 63 FR 24121 (1998).
     Electronic Filers: Comments may be filed electronically 
using the Internet by accessing the ECFS: http://fjallfoss.fcc.gov/ecfs2/.
     Paper Filers: Parties who choose to file by paper must 
file an original and one copy of each filing. If more than one docket 
or rulemaking number appears in the caption of this proceeding, filers 
must submit two additional copies for each additional docket or 
rulemaking number.
    Filings can be sent by hand or messenger delivery, by commercial 
overnight courier, or by first-class or overnight U.S. Postal Service 
mail. All filings must be addressed to the Commission's Secretary, 
Office of the Secretary, Federal Communications Commission.
     All hand-delivered or messenger-delivered paper filings 
for the Commission's Secretary must be delivered to FCC Headquarters at 
445 12th St. SW., Room TW-A325, Washington, DC 20554. The filing hours 
are 8:00 a.m. to 7:00 p.m. All hand deliveries must be held together 
with rubber bands or fasteners. Any envelopes and boxes must be 
disposed of before entering the building.
     Commercial overnight mail (other than U.S. Postal Service 
Express Mail and Priority Mail) must be sent to 9300 East Hampton 
Drive, Capitol Heights, MD 20743.
     U.S. Postal Service first-class, Express, and Priority 
mail must be addressed to 445 12th Street SW., Washington, DC 20554.
    People with Disabilities: To request materials in accessible 
formats for people with disabilities (braille, large print, electronic 
files, audio format), send an email to [email protected] or call the 
Consumer & Governmental Affairs Bureau at 202-418-0530 (voice), 202-
418-0432 (tty).

Summary of Public Notice

    The FCC's Office of Engineering and Technology (OET) announced the 
release of new software to perform interference analyses using the 
methodology described in its Bulletin No. 69 (OET-69). This software, 
called TVStudy, provides analysis of coverage and interference of full-
service digital and Class A television stations. The Commission plans 
to use this new software in connection with the proposed broadcast 
television spectrum incentive auction (incentive auction). OET seeks 
comment on the software generally, as well as the identification of any 
errors, unexpected behaviors, or anomalous results produced in running 
the software. In addition, OET solicits comment on the implementation 
of various analytical elements in the software that are not 
specifically addressed in OET-69.

Background

    The Commission developed the software that is currently used to 
implement OET-69 to support the DTV transition, and it has subsequently 
been used to analyze applications to modify the DTV Table of Channel 
Allotments. As such, the software programs developed by the FCC for 
those purposes are based fundamentally on source code and data from the 
1990s and earlier. Since that time, some of the underlying datasets 
have evolved or have been replaced. In addition, parties have gained 
sufficient experience to have offered FCC staff informal feedback on 
the existing programs' relative strengths and weaknesses.
    It is with these matters in mind that we have developed the TVStudy 
software. The new software operates on modern computer systems, and it 
runs much faster, provides greater accuracy in modeling and analysis, 
and is easier to use and more versatile than the existing software. In 
addition, the TVStudy software will allow us to perform the types of 
analyses that are needed to support the proposed incentive auction.
    An important component of the proposed incentive auction is the 
repacking of broadcast television stations, including the potential 
reassignment of stations to new operating channels. The Middle Class 
Tax Relief and Job Creation Act of 2012 (Spectrum Act) requires the 
Commission to ``make all reasonable efforts to preserve, as of the date 
of the enactment of this Act, the coverage area and population served 
of each broadcast television licensee, as determined using the 
methodology described in OET Bulletin 69 of the Office of Engineering 
and Technology.'' OET-69 describes a methodology that divides the area 
within a digital television station's noise-limited coverage contour 
into approximately rectangular ``grid cells,'' and then evaluates these 
cells for coverage and, where present, interference. The Commission's 
Incentive Auction NPRM, See Expanding the Economic and Innovation 
Opportunities of Spectrum Through Incentive Auctions, Notice of 
Proposed Rulemaking, FCC 12-118, Docket No. 12-268, 27 FCC Rcd. 12357 
(2012) (Incentive Auction NPRM). Available at http://transition.fcc.gov/Daily_Releases/Daily_Business/2012/db1002/FCC-12-118A1.pdf proposes to define the ``coverage area'' of full-power 
stations as the geographic area within a station's noise-limited 
contour where its signal strength is predicted to exceed the noise-
limited service level, both levels calculated on an F(50,90) basis. 
Similarly, the Incentive Auction NPRM proposes to define the ``coverage 
area'' for Class A stations as the geographic area within a station's 
protected contour where its signal strength is predicted to exceed the 
protected service level, both levels calculated on an F(50,90) basis.
    The Incentive Auction NPRM also proposes to define the ``population 
served'' by full-power stations as the population within a station's 
noise-limited contour where its signal strength is predicted to exceed 
the noise-limited service level on an F(50,90) basis and is not subject 
to predicted interference from other stations, using the protection 
ratios specified in OET-69 and the rules. Similarly, the Incentive 
Auction NPRM proposes to define the ``population served'' by Class A 
stations as the population within a station's protected contour where 
its signal strength is predicted to exceed the protected service level 
on an F(50,90) basis and is not subject to predicted interference from 
other stations, using the protection ratios specified in OET-69 and the 
rules.
    OET-69 defines certain parameter values for programmers to use when 
developing the software to implement OET-69's methodology. In 
particular, Table 4 of OET-69 lists parameter values used by the 
Fortran Code for the Longley-Rice (L-R) radio signal propagation model 
used in the implementing software, Tables 5A and 5B list the D/U ratios 
to be used in predicting interference, Table 6 describes the 
performance of the assumed receiving antennas, and Table 8 describes 
the elevation-plane performance of the assumed transmitting antennas. 
The foregoing is not an exhaustive list; OET-69 provides additional 
definitions and guidance. OET-69 does not, however, specify all of the 
parameters and methods required when developing software to implement 
OET-69's methodology. The choices made in implementing the methodology 
of OET-69 can produce different results,

[[Page 11131]]

and such differences can affect a station's coverage area and 
population served. By making the new TVStudy software as well as 
reference copies of the various databases necessary to run that 
software available to the public, we provide a means for implementing 
the OET-69 methodology that ensures consistency in the results obtained 
by the Commission and interested parties.

TVStudy Software

    The new TVStudy software is designed for making rapid coverage and 
interference calculations involving many stations and provides highly-
detailed outputs. It is intuitive in its operation and rapidly produces 
useful results. It has been developed in two parts: (1) A graphical 
user interface (implemented in Java), used to establish the parameters 
of the study and which draws data from appropriate databases; and (2) 
an analysis engine (implemented in C), which makes the necessary 
calculations to establish coverage and interference. The outputs 
include both summaries of area and population by station, and detailed 
signal level predictions by cell.
    We are interested in feedback that discusses the capabilities of 
the TVStudy software to support the incentive auction and to implement 
whatever decisions are made in the rulemaking proceeding. For example, 
one of the options discussed in the Incentive Auction NPRM requires 
identifying specific populations presently subject to interference so 
that new interference is not created. As a practical matter, such an 
approach requires maintaining a database of interference status at the 
cell level. The present software implementing OET-69 that the 
Commission uses for processing applications for new TV stations and 
modifications to existing stations does not support creation of such a 
database. The present software was designed for processing individual 
applications rather than the concurrent study of complete, nationwide 
assignments. We also seek comment on the new software generally as a 
tool for analyzing the service area coverage, population served, and 
interference received by broadcast television stations.
    In developing the TVStudy software, we have identified various 
parameter choices consistent with but not specified in OET-69 that we 
believe are necessary for improved accuracy in our modeling and 
analysis. We incorporated ``soft-switches'' into the TVStudy software 
to permit the user to evaluate the effects of the different choices. We 
note that the different parameter choices may yield results for both 
coverage and interference different from legacy versions of software 
that have been used in the past.
    In conducting the proposed incentive auction, an important 
objective is that we use software with improved accuracy and that makes 
use of the best available data to compute estimates of the coverage 
area and population served of each broadcast television licensee 
consistent with the provisions of the Spectrum Act. To that end, we 
solicit feedback from stakeholders, experts, and others on the 
implementation of the TVStudy software. Specifically, we discuss below 
and invite comment in the following areas:

 Population data
 Terrain data
 Treatment of inaccurate data in FCC database
 Treatment of antenna beam tilt
 Calculation of depression angles
 Level of precision of geographic coordinates
 Establishment of calculation (cell) grid
 Treatment of internal (Longley-Rice) warnings

    Population Data. Population coverage in the original DTV Table of 
Allotments was calculated using data from the 1990 U.S. Census. 
According to the U.S. Census, the population of the United States 
increased by about 24 percent between 1990 and 2010, and the 
distribution of population has also changed. Because the use of 1990 
Census data in the present OET-69 software is unlikely to produce an 
accurate depiction of present-day DTV station population coverage, the 
TVStudy software is designed to use 2010 U.S. Census data.
    Terrain Data. Three-arcsecond digital terrain data are used in the 
present OET-69 software that we used to develop the original DTV Table 
of Allotments. This means that land elevations are reported every three 
seconds of geographic latitude and longitude (about every 300 feet). 
The three-arcsecond database was produced primarily by automatically 
scanning and interpolating large-scale (such as 1:250,000) paper maps, 
which often used relatively coarse elevation contours. A number of 
versions of the three-arcsecond terrain database were released by 
various agencies, some of which contained errors. Moreover, the three-
arcsecond terrain database is no longer being revised, maintained, or 
supported by the U.S. Geological Survey. A new one-arcsecond terrain 
database, which has greater resolution (elevation points are spaced 
about every 100 feet), has replaced the old three-arcsecond terrain 
database. Additionally, the one-arcsecond terrain database is derived 
from smaller-scale (e.g. 1:24,000) topographic maps with more granular 
elevation data, and the method for extracting elevation data from those 
maps has been improved. Because continued use of an unsupported terrain 
database is likely to lead to obsolescence and potentially inaccurate 
results, the TVStudy software is designed to use one-arcsecond terrain 
data.
    Treatment of Inaccurate Data in FCC Database. We recognize that 
there may be instances where the information entered into the FCC's 
broadcast station database (CDBS) may not be fully accurate. Examples 
may include:

 Negative values for beam tilt
 Swapped values for mechanical beam tilt and orientation
 Missing maximum values for directional antenna patterns
 Missing or incorrect directional antenna flags
 ERP value entered in dBk instead of kilowatts

    These sorts of inaccuracies can lead to incorrect or nonsensical 
results when used in a computer program to predict coverage and 
interference. We are not proposing to modify the information in the 
underlying CBDS database. However, we seek comment on what methods we 
should use to detect information that may be inaccurate and what 
correction methods we should incorporate into our use of that 
information.
    Treatment of Antenna Beam Tilt. All DTV stations operate 
directionally in the elevation plane. That is, the transmitting antenna 
is engineered to focus energy toward populated areas while minimizing 
energy radiated skyward. To accomplish this, most transmitting antennas 
are tilted downward, usually uniformly (electrically) but sometimes 
non-uniformly (mechanically), or both. The actual amount of tilt, if 
any, is contained in the CDBS record for each station. The present 
software used to implement OET-69 uses elevation patterns with a fixed 
electrical beam tilt (e.g., 0.75[deg] for full-power stations operating 
on UHF channels), and in the development of the original DTV Table of 
Allotments, the actual amount of tilt given in CDBS was ignored. As a 
result of ignoring the actual beam tilt, the direction of main beam 
radiation used to project coverage in the present software may be 
incorrect, which can effectively cause it to ``miss'' the population 
being served. We believe that a better practice in implementing OET-69 
would be to use

[[Page 11132]]

the value for electrical downtilt specified in CDBS to correct the 
generic elevation pattern such that the main beam is at the angle 
specified in CDBS rather than using a fixed value. Because sufficient 
information is typically not available to correctly project the antenna 
patterns of stations having mechanical beam tilt, we do not propose to 
use mechanical beam tilt in OET-69 calculations.
    Calculation of Depression Angles. The depression angle is the 
vertical angle between the horizontal (at the location of the DTV 
transmitting antenna) and the location of the receive site under study 
(cell centroid). An error in the present software used to implement 
OET-69 and to develop the original DTV Table of Allotments caused this 
angle to be incorrectly calculated based on the antenna height above 
ground, rather than the height above mean sea level. This error can 
cause the radiated power toward the cell under study to be incorrectly 
calculated, particularly for stations that have antennas atop tall 
mountains (as opposed to tall towers). The TVStudy software is designed 
to avoid causing this error.
    Precision of Geographic Coordinates. The fundamental unit of the 
U.S. Census is the Census Block, which specifies locations to a 
precision of 0.0000001[deg] (about 0.0004 seconds) of latitude and 
longitude. Earlier versions of software implementing OET-69 rounded or 
truncated this location data to the nearest second, discarding some 
three orders of precision. This action often causes the centroid 
locations of cells under study to be shifted. While the original reason 
for this reduction in precision are unknown, we believe that it may 
have been related to computational limitations at the time of 
development. At this time, there appears to be no reason to 
intentionally reduce numerical precision and we believe that full-
precision location data should be used in the TVStudy software.
    Establishment of Calculation (cell) Grid. The present OET-69 
software is designed to establish calculation grids that are for the 
most part unique to each station considered. This approach requires 
that all desired and undesired signal levels be calculated for each 
cell of each station studied and results in cell-level data that cannot 
be directly compared between different potential channel allotments 
and/or stations. Another approach is to establish a single, global 
calculation grid, common to all stations. Such a global approach 
results in data that can be used to directly compare interference 
impacts at the cell level, and also speeds calculations since the study 
grid only needs to be established one time. The TVStudy software is 
designed to generate and use a global calculation grid.
    Treatment of Internal (Longley-Rice) Warnings. The propagation 
algorithm underlying OET-69 is the Irregular Terrain Model (ITM), also 
known as Longley-Rice (or simply L-R). It is based in part on actual 
measurements of path loss made by the Department of Commerce over 
different terrain profiles. Although the measurement data collected 
were used to create generalized computational models of different types 
of terrain profiles, not every single terrain profile possible was 
represented. In particular, terrain profiles lying outside the range of 
collected data still produce results, but those results are ``flagged'' 
as being ``unusable or dubious.''
    The software used to develop the original DTV Table of Allotments 
treated cells having such ``flags'' (whether from desired or 
interfering stations) as having coverage. This determination results in 
areas where we have no real information about predicted coverage or 
interference. Such cells are assumed to have coverage, even if 
neighboring cells do not. This treatment of ``flagged'' results 
implemented the Commission's decision that assumption of service is 
appropriate where the Longley-Rice propagation model indicates that 
service calculations may be dubious or unreliable. Comparisons with 
other propagation models suggest that the ``flagged'' results are 
typically not unreasonable.
    We note that while this approach was taken for purposes of 
implementing OET-69, a different approach was taken in implementing OET 
Bulletins 72 and 73 (OET-72 and OET-73, respectively) dealing with the 
availability of TV service for purposes of the Satellite Home Viewer 
Act and subsequent legislation. In those cases, the L-R propagation 
model is used differently and for different purposes. Specifically, 
OET-72 and OET-73 use the L-R model to estimate whether a TV station's 
signal is receivable at an individual location (a viewer's home), 
whereas OET-69 estimates a station's signal coverage, population served 
and interference received over the entire geographic area it serves. 
With regard to OET-72 and OET-73, the Commission found that ignoring 
the appearance of so-called ``error codes'' and accepting the 
calculated field strength value was appropriate for determining 
eligibility for satellite delivery of network programming at individual 
locations.
    We ask whether we should to continue to assume coverage in areas 
that have flagged results in implementing the Commission's decision 
that assumption of service is appropriate where the Longley-Rice 
propagation model indicates that service calculations may be dubious or 
unreliable. If not, we ask what assumptions should be made relative to 
coverage and population served under such conditions to more 
effectively implement the Commission's decision.

Availability of Developmental Software and Data

    The Commission is making available its developmental TVStudy 
software and the data required to run it on its Web site at: http://data.fcc.gov/download/incentive-auctions/OET-69/.
    Installation and operating instructions are included as separate 
files.
    The software was developed on an Apple iMac, but it is expected 
that the source code can be compiled on other Unix-like platforms (e.g. 
Linux). Compatibility of the C source-code with Microsoft Windows-based 
compilers is not guaranteed, but only minor modification would be 
expected. The Java code, which was developed in Java version 1.6, is 
expected to be platform independent. In addition to the source code, a 
fully-compiled version of the software is supplied for use on Apple 
computers running OS10.6 or higher. The software also requires certain 
MySQL client libraries, which can be obtained by installing MySQL 
Community Server (available at no cost from Oracle). To ensure 
compatibility, MySQL Community Server version 5.529 is recommended.
    Parties seeking to evaluate the TVStudy software will also need 
various data files for terrain and population. Some of the necessary 
data files are quite large and so have been archived using TAR and GZip 
(collectively TGZ) and encoded using PAR2 to facilitate error detection 
and correction. The necessary data files for population and terrain are 
supplied at the URL given above, together with a reference copy of CDBS 
for television stations as of February 22, 2012.

Federal Communications Commission.
Julius P. Knapp,
Chief, Office of Engineering and Technology.
[FR Doc. 2013-03486 Filed 2-14-13; 8:45 am]
BILLING CODE 6712-01-P