Quantitative Assessments of

Spectrum Usage

U.S. Department of Commerce

Penny Pritzker, Secretary

Lawrence E. Strickling, Assistant Secretary

for Communications and Information

November 2016
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iii

CONTENTS

ABBREVIATIONS...................................................................................................................... iv

EXECUTIVE SUMMARY ......................................................................................................... vi

1. INTRODUCTION......................................................................................................................1

1.1 Background............................................................................................................................1

1.2 Objective................................................................................................................................2

1.3 Approach................................................................................................................................3

1.4 Summary................................................................................................................................6

2. DESCRIPTION OF TRANSMIT AND RECEIVE STATION DATA ..............................10

2.1 Introduction..........................................................................................................................10

2.2 Transmit Station Data ..........................................................................................................10

2.3 Receive Station Data............................................................................................................11

2.4 Time of Usage......................................................................................................................11

3. METHODOLOGY FOR COMPUTING TRANSMIT STATION CONTOURS .............12

3.1 Introduction..........................................................................................................................12

3.2 Methodology for Computing Transmit Station Contours....................................................12

4. METHODOLOGY FOR COMPUTING RECEIVE STATION CONTOURS.................17

4.1 Introduction..........................................................................................................................17

4.2 Methodology for Computing Receive Station Contours .....................................................17

4.3 Radio Astronomy Observatories..........................................................................................21

5. PERCENTAGE OF POPULATION IMPACTED AND GEOGRAPHIC 

AVAILABILITY CALCULATIONS ........................................................................................22

5.1 Introduction..........................................................................................................................22

5.2 Percentage of Population Impacted Calculation..................................................................22

5.3 Percentage of Geographical Availability Calculation .........................................................22

6. OVERVIEW OF FEDERAL OPERATIONS......................................................................24

6.1 Introduction..........................................................................................................................24

6.2 Overview of Federal Systems..............................................................................................24

7. CALCULATION OF TOTAL SPECTRUM USAGE..........................................................31

7.1 Introduction..........................................................................................................................31

7.2 Total Spectrum Usage in Quantitative Assessment Frequency Bands................................31

8. RESULTS OF QUANTITATIVE ASSESSMENTS.............................................................57

8.1 Introduction..........................................................................................................................57

8.2 1300-1390 MHz Band .........................................................................................................57

8.3 1675-1695 MHz Band .........................................................................................................59

8.4 2700-2900 MHz Band .........................................................................................................61

8.5 2900-3100 MHz Band .........................................................................................................63

8.6 3100-3550 MHz Band .........................................................................................................65

APPENDICES
iv

ABBREVIATIONS

AF United States Air Force

AR United States Army

ASR Airport Surveillance Radar

ATC Air Traffic Control

CDA Command and Data Acquisition 

dB Decibel

dBi Decibels relative to an isotropic antenna

dBW Decibels relative to a watt

DCP Data collection platform

DCPR Data Collection Platform Report

DHS Department of Homeland Security

DOC Department of Commerce

DOE Department of Energy

DOD Department of Defense

DOT Department of Transportation

DC Duty cycle

EIRP Equivalent isotropically radiated power

EMWIN Emergency Managers Weather Information Network

EPA Environmental Protection Agency

FAA Federal Aviation Administration

GHz Gigahertz

GMF Government Master File

GOES Geostationary Operational Environmental Satellites

GRB GOES Rebroadcast

GVAR GOES VARiable

HRIT High Rate Information Transmission

IRAC Interdepartment Radio Advisory Committee

ITM Irregular Terrain Model
v

km Kilometers

Log Common logarithm

MARAD Maritime Administration

MC United States Marine Corps

MDL Multi-use data link

MHz Megahertz

MOU Memorandum of Understanding 

MPAR Multi-function phased array radar

N United States Navy

NAS National Airspace System

NASA National Aeronautics and Space Administration 

NDS Nuclear Detonation and Detection System

NESDIS National Environmental Satellite Data and Information Service

NEXRAD Next Generation Radar

NOAA National Oceanic and Atmospheric Administration 

NWS National Weather Service

NTIA National Telecommunications and Information Administration

PPSG Policy and Plans Steering Group

PSD Power spectral density

RACON Radar Beacon

SD Sensor Data

SENSR Spectrum Efficient National Surveillance Radar

SLDSC Saint Lawrence Seaway Development Corporation

TARS Tethered Aerostat Radar Systems

UAS Unmanned Aircraft System

US&P United States and Possessions

USCG United States Coast Guard
vi

EXECUTIVE SUMMARY

In this report, the National Telecommunications and Information Administration (NTIA) 

presents a summary of the results of its quantitative assessments of spectrum usage in response 

to the 2013 Presidential Memorandum entitled Expanding America’s Leadership in Wireless 

Innovation. Through this memorandum, the President sought to make more spectrum available 

by allowing and encouraging shared access by commercial providers to spectrum that is 

currently allocated for federal use. As the President’s memorandum makes clear, spectrum 

sharing can enhance efficiency among all users and can expedite commercial access to additional 

spectrum bands where technically and economically feasible. Accordingly, the memorandum 

directed NTIA and the federal agencies to take a number of steps to accelerate shared access to 

spectrum, such as conducting quantitative assessments of frequency bands that have the greatest 

potential to be shared with non-federal users without adversely affecting agencies’ missions.

In response to the President’s directive, NTIA’s Plan for Quantitative Assessments of 

Spectrum Usage (NTIA Plan) called for the evaluation of existing use in 960 megahertz of 

spectrum in five frequency bands previously identified for potential future sharing studies. 

These bands are: 1300-1390 MHz, 1675-1695 MHz, 2700-2900 MHz, 2900-3100 MHz, and 

3100-3550 MHz. The NTIA Plan required applicable agencies to verify system characteristics 

associated with their frequency assignments to enable calculation of the geographic coverage 

area used by these systems. The NTIA Plan further required each applicable agency to provide 

estimates of time of use which, together with the coverage area and other metrics, allows for an 

overall approximation of the extent to which each system uses its assigned spectrum. The 

cumulative total of each agency’s use within a range of frequencies and across systems using a 

tool developed by NTIA serves as the quantitative assessment for the particular band under 

review. In bands and locations where multiple agencies have systems, NTIA has aggregated the 

data in this summary as prescribed by the 2013 Presidential Memorandum. 

The 2013 Presidential Memorandum and NTIA Plan also required the applicable

agencies to provide information on projected increases in their spectrum usage and needs, and to 

identify where access to non-federal spectrum could aid in fulfilling agency missions. The NTIA 

Plan also requested these agencies identify relevant and essential mission-related factors that 

must be considered.

These quantitative assessments can be used as an intermediate step in a process for 

identifying and prioritizing strategic options for potential repurposing of bands. The information 

developed in the quantitative assessments will help NTIA and the White House’s Spectrum 

Policy Team, in consultation with the agencies, determine the extent to which frequencies

assigned to these agencies could be further evaluated for sharing with commercial users, 

particularly in major metropolitan areas. Based on the quantitative assessments and associated 

implications, this report identifies potential sharing opportunities suitable for further examination 

through feasibility studies. Such detailed evaluations would analyze technical, operational, and 

cost considerations to ascertain whether such frequencies are appropriate candidates for 

repurposing for shared federal/non-federal use.
1. INTRODUCTION

1.1 Background 

To promote economic growth and unleash the potential of wireless broadband, President 

Obama’s 2010 Presidential Memorandum unveiled an initiative to reform spectrum policy and

increase the amount of spectrum available for commercial wireless broadband services. The 

2010 Presidential Memorandum specifically directed the Secretary of Commerce, working 

through the National Telecommunications and Information Administration (NTIA) and in 

collaboration with the Federal Communications Commission (FCC), to identify and make 

available 500 megahertz of federal and non-federal spectrum by 2020 for expanded wireless 

broadband use.1The launch of this initiative represented a critical first step toward creating a 

more efficient and innovative wireless broadband infrastructure and catalyzing new private 

sector investment and economic activity by making more spectrum available for emerging 

technologies.

In October 2010, pursuant to the 2010 Presidential Memorandum, NTIA, with input from 

the Policy and Plans Steering Group (PPSG), issued a plan and timetable to achieve the 

President’s 500 megahertz goal over the next ten years.2The plan and timetable took into

account the need to ensure no loss of critical existing federal, state, local, and tribal government 

capabilities, the international implications, and the need for appropriate enforcement mechanisms 

and authorities.3The Ten-Year Plan identified more than 2,200 megahertz of federal and nonfederal spectrum for evaluation, proposed a process for evaluating candidate bands, and set forth 

the steps necessary to select and make spectrum available for commercial wireless broadband 

services.

On June 14, 2013, President Obama issued a second, related memorandum entitled 

Expanding America’s Leadership in Wireless Innovation, through which the Administration 

sought to make more spectrum available for commercial use by allowing and encouraging shared 

access by commercial providers to spectrum that is currently allocated for federal use.4 At the 

 

1

See Memorandum for the Heads of Executive Departments and Agencies, Unleashing the Wireless Broadband

Revolution (rel. June 28, 2010), published at 75 Fed. Reg. 38387 (July 1, 2010), available at

http://www.whitehouse.gov/the-press-office/presidential-memorandum-unleashing-wireless-broadband-revolution

(2010 Presidential Memorandum).

2 NTIA, Plan and Timetable to Make Available 500 Megahertz of Spectrum for Wireless Broadband (Oct. 2010), 

available at http://www.ntia.doc.gov/files/ntia/publications/tenyearplan_11152010.pdf (Ten-Year Plan). The PPSG 

is an advisory group of senior federal officials who advise NTIA on achieving the objectives of the 2010 

Presidential Memorandum. See 2010 Presidential Memorandum at § 1(c).

3

Id. at § 1(b).

4

See Memorandum for the Heads of Executive Departments and Agencies, Expanding America’s Leadership in 

Wireless Innovation (rel. June 14, 2013), published at 78 Fed. Reg. 37431 (June 20, 2013), available at

http://www.whitehouse.gov/the-press-office/2013/06/14/presidential-memorandum-expanding-americas-leadershipwireless-innovatio (2013 Presidential Memorandum).
2

same time, the President again recognized the need to ensure that federal, state, local, tribal, and 

territorial governments are able to maintain mission critical capabilities that depend on spectrum 

today, as well as effectively and efficiently meet future requirements. The 2013 Presidential 

Memorandum recognized the ongoing efforts spawned three years earlier and re-emphasized

how spectrum sharing can enhance efficiency among all users and expedite commercial access to 

additional spectrum bands where technically and economically feasible. The second 

memorandum reflected a new reality of spectrum management in which we can achieve 

spectrum efficiency by maximizing shared access to spectrum between federal and non-federal 

users, noting that federal agencies have long shared spectrum allocated for federal use. This new 

spectrum management approach recognizes that it is becoming increasingly difficult to identify 

feasible alternatives for relocating essential federal capabilities and services without incurring 

substantial costs and imposing significant operational limitations and delays. Consistent with 

this shift to promoting more spectrum sharing in federal and non-federal bands, the 2013 

Presidential Memorandum directed federal agencies to take a number of steps to accelerate 

shared access to spectrum, including making quantitative assessments of actual spectrum usage 

in frequency bands that NTIA had previously identified and prioritized pursuant to the PPSG 

efforts noted above.

5

Since the release of its Ten-Year Plan, NTIA has issued six interim progress reports 

summarizing and assessing the progress that has been made during each reporting period.6

The 2013 Presidential Memorandum required NTIA, in consultation with the White House 

Spectrum Policy Team and appropriate agencies, to develop a plan in the Fourth Interim Report

directing the applicable agencies to provide quantitative assessments of their actual usage of the 

spectrum in the frequency bands that NTIA had previously identified and reprioritized in its 

Third Interim Report.

7 NTIA’s Fourth Interim Report included a Plan for Quantitative 

Assessments of Spectrum Usage, setting forth the methodology for the quantitative assessments

called for by the President.

8

1.2 Objective 

The 2013 Presidential Memorandum stipulated that each agency’s assessments are to be 

prepared according to such metrics and other parameters as are reasonably necessary to 

determine the extent to which spectrum assigned to the agency potentially could be made 

available for sharing with or release to commercial users, particularly in major metropolitan 

areas, without adversely affecting agencies’ missions especially those related to national 

security, law enforcement, and safety of life. This report summarizes the results of the 

quantitative assessments and makes findings to support the development of further 

 

5

See id. at § 3(a).

6

See 2010 Presidential Memorandum at § 1(d); see also NTIA 500 MHz Initiative, available at

http://www.ntia.doc.gov/category/500-mhz-initiative. 

7

See NTIA, Third Interim Progress Report on the Ten-Year Plan and Timetable at 12-13 (Nov. 29, 2012), available

at http://www.ntia.doc.gov/files/ntia/publications/third_interim_progress_report_final.pdf (Third Interim Report).

8 NTIA, Fourth Interim Progress Report on the Ten-Year Plan and Timetable and Plan for Quantitative 

Assessments of Spectrum Usage at Appendix A (June 5, 2014), available at 

http://www.ntia.doc.gov/files/ntia/publications/fourth_interim_progress_report_final.pdf (Fourth Interim Report).
3

recommendations, as appropriate, for future feasibility studies. Section 3(b) of the 2013 

Presidential Memorandum provides that “NTIA shall release a summary of the assessments 

publicly to the extent consistent with law.” It provides further that “NTIA and the Spectrum 

Policy Team shall make any appropriate recommendations regarding the possible availability of 

spectrum in the subject bands for innovative and flexible commercial uses, including broadband, 

taking into account factors such as the nature of the Federal systems in the bands and the extent 

to which those systems occupy and use the bands.”

9

1.3 Approach 

NTIA’s Fourth Interim Report identified 960 megahertz of spectrum in five frequency 

bands for the quantitative assessments: 1300-1390 MHz, 1675-1695 MHz, 2700-2900 MHz, 

2900-3100 MHz, and 3100-3550 MHz. To supplement the parameters already associated with 

their frequency assignments contained in the Government Master File (GMF), NTIA’s Plan for 

Quantitative Assessments of Spectrum Usage required the affected agencies to submit additional 

data for each system’s individual transmitting and receiving stations as necessary to develop an 

approximation of each system’s actual use of the spectrum. The data includes parameters for 

spectrum (frequency and bandwidth), geographic area, and estimated time of usage for each 

operation in accordance with the metrics in the methodology stipulated in the plan. Based on 

each agency’s assessment of the most up-to-date and validated parameters and data elements, the 

key metric that NTIA derived from such data is the cumulative Total Spectrum Usage. Total 

Spectrum Usage represents the cumulative data resulting from the aggregation of each agency’s

quantitative assessment using three independent components: frequency (bandwidth) use, 

geographic use, and time of use. The findings based on this data can be used as one input to 

narrow down, select, and prioritize the identified frequency bands for more detailed feasibility 

studies. 

In June 2014, NTIA requested each agency with current operations in the bands under 

review for the quantitative assessment to report on their projected usage, termination, and future 

developments.10 It asked each applicable agency to provide information regarding planned new 

uses, expected expansion of current uses, and potential relocation or cessation of use, projecting 

where and when these future uses or changes would increase or decrease its spectrum usage in

the bands under review. 

From June 5, 2014 to June 5, 2015, in accordance with the Plan for Quantitative 

Assessments of Spectrum Usage, NTIA and the affected agencies took the following steps:

- NTIA provided each agency with additional detailed instructions, including guidance 

on the methodology used in performing the quantitative assessment, along with a list 

 

9

2013 Presidential Memorandum at § 3(b).

10 Reference to termination or cessation of frequency assignments and relocation of systems to other frequencies are 

only related to the normal NTIA frequency assignment process as opposed to repurposing considerations which 

requires detailed feasibility studies, as well as specific accommodations such as comparable spectrum. 
4

of GMF frequency authorization and spectrum certification data for the bands 

identified in the NTIA Plan.11

- Each agency reviewed and verified its frequency assignment and spectrum 

certification data.

- After verification, each agency updated the information for any assignments omitted 

from the list provided by NTIA, and for any station, system, or facility using or 

authorized to use the bands identified for the quantitative assessment that was not 

included in the GMF data or not otherwise required to obtain an assignment from 

NTIA (e.g., receivers).

- For each assignment, each agency provided an estimated percentage of time of actual 

use, based on the metric provided in the plan to represent access and availability 

needs for mission or operational requirements.

- Using the data provided, validated and supplemented by the agencies, NTIA 

computed the spectrum usage contours and the estimated percentage of the population 

impacted using a new analytical tool NTIA developed for the purpose of compiling 

and summarizing usage.

12

The methodology used by NTIA to compute Total Spectrum Usage was coordinated with the 

federal agencies through the Technical Subcommittee of the Interdepartment Radio Advisory 

Committee (IRAC).

In August 2015, NTIA reminded the affected agencies that the Plan for Quantitative 

Assessments of Spectrum Usage required them to address projected future spectrum usage in 

each band under review and to provide NTIA supplemental information on the following: all 

expected expansion of current systems and uses (e.g., geographic expansion, additional 

frequencies or bandwidth, and increased time of use); all planned new systems and uses; and any 

potential relocation, cessation, or modification of current systems and uses. For each of these 

systems and uses, NTIA asked these agencies to provide any available data elements for the 

transmit and receive stations listed in the Plan for Quantitative Assessments of Spectrum Usage

along with the information that would otherwise be required by Section 10.8.1 of the NTIA 

Manual.

13 At a minimum, if such data and information was not readily available, NTIA 

requested that the agencies specifically identify for each system or use:

- the affected geographic location(s);

 

11 The quantitative assessment is a snapshot of the federal frequency assignment data from the GMF as of December 

2015.

12 The spectrum usage contours were developed assuming antenna heights and power thresholds consistent with 

terrestrial systems. The geographic usage contours do not take into account United States and Possessions (US&P) 

frequency assignments.

13 NTIA Manual of Regulations and Procedures for Federal Radio Frequency Management at § 10.8.1 (September 

2015 Revision of the May 2013 Edition) (NTIA Manual).
5

- projected timelines (e.g., for submission of new or modified requests for certification 

of spectrum support, field testing, procurement, deployment, expansion, relocation, 

cessation, etc.);

- other federal agencies that could benefit or be affected by such changes (e.g., 

enhanced or consolidated services or systems, reduced or increased interference risks, 

reduced or increased costs, etc.); and

- how such projected changes would increase or decrease the agency’s Total Spectrum 

Usage in the bands under review (i.e., geographic coverage, necessary bandwidth, and 

estimated time of use). 

NTIA also requested that these agencies provide a description of how and where access 

to non-federal spectrum bands could aid in fulfilling their mission (as well as any other agencies’ 

missions). This included relevant and detailed information regarding:

- candidate frequency band(s) currently allocated to non-federal use on an exclusive or 

primary basis;

- the type(s) of federal operations that would be conducted in such band(s) and its 

(their) necessary bandwidth and performance requirements;

- the likely source(s) of equipment and technology for such systems (i.e., commercial 

or government off-the-shelf, repurposed specialized/proprietary, new or undeveloped, 

etc.);

- the type, size, and scope of the geographic area(s) in which such operations would 

occur; and

- the estimated percentage of time the band(s) would be used within the geographic 

area(s).

Throughout this process, NTIA consulted with federal agency representatives on the 

Spectrum Working Group of the PPSG on the progress and challenges associated with accurately 

estimating and assessing actual spectrum usage.

The quantitative assessments are one input in a process for identifying and prioritizing 

strategic options for detailed feasibility studies to examine potential sharing options in a band.

14

This report documents the results of the actions taken by NTIA and the affected agencies in 

performing the quantitative assessments based on the information derived from NTIA’s tool. 

Section 2 describes the data used in the assessments. Sections 3 and 4 describe the 

 

14 See NTIA, An Assessment of the Viability of Accommodating Wireless Broadband in the 1755-1850 MHz Band

(Mar. 2012), available at

http://www.ntia.doc.gov/files/ntia/publications/ntia_1755_1850_mhz_report_march2012.pdf. The detailed 

feasibility studies will consider all relevant scenarios and potential impacts to the federal systems which could 

include the effects of aggregate interference.
6

methodologies to compute the transmit and receive station spectrum usage contours. The 

population impacted and geographic availability calculations are described in Section 5.15

Section 6 provides an overview of the federal operations in the quantitative assessment 

frequency bands. Section 7 describes the calculation of Total Spectrum Usage. The detailed

results of the quantitative assessments are presented in Section 8. 

1.4 Summary

Based on the quantitative assessments, NTIA has identified several bands with potential 

sharing opportunities, contingent upon the successful completion of feasibility studies. The more 

detailed evaluation of a band for sharing would need to take into account all current and future 

uses in a band, including those that can occur anywhere in the US&P, as well as technical, 

operational, and cost considerations.

16

While the results of quantitative assessments can assist in representing an approximation 

of spectrum use, the nature of the federal operations and mission requirements may directly 

impact the specific risks associated with sharing feasibility considerations. For example, while 

some federal systems may operate intermittently, these systems may support operations such as 

critical national security applications, which require high spectrum availability when and where 

needed. 

1.4.1 Overview of Quantitative Assessments Results. Using the criteria in Table 1-1, 

NTIA identified spectrum for future feasibility studies to assess potential sharing opportunities. 

The quantitative assessments and the associated criteria are components of a complex process for 

determining options for detailed sharing feasibility studies.

Table 1-1. Criteria Used to Identify Potential Sharing Opportunities

Sharing 

Opportunity

Criteria

Frequency 

Sharing

No frequency assignments (excluding band, airborne, and United States and 

Possessions (US&P) frequency assignments) within a 5 megahertz band segment

Geographic 

Sharing

For approximately 70% of the 5 megahertz band segments the following criteria 

must be satisfied:

- percentage of population impacted: less than approximately 60%

- percentage of geographic availability: greater than approximately 50%

Time 

Sharing

Station time of usage less than 10% for approximately 70% of the frequency 

assignments within a 5 megahertz band segment

The results of the quantitative assessments were used to identify the bands for which 

potential future feasibility studies to assess potential sharing opportunities would be most 

beneficial, as shown in Table 1-2.

 

15 For the purpose of the quantitative assessments, geographic availability represents the area as a percentage of the 

contiguous United States that geographically is not covered by the spectrum usage contours. 

16 See Ten-Year Plan at 12-13. 
7

Table 1-2. Potential Feasibility Studies Based on Quantitative Assessment of Spectrum 

Usage

Frequency Band 

(MHz)

Types of Feasibility Studies

Frequency Sharing Geographic Sharing Time Sharing

1300-1350 No No No

1350-1390* No No Yes

1675-1695 No Yes No

2700-2900 No No No

2900-3100 No Yes No

3100-3505* No Yes Yes

3505-3550* Yes Yes Yes

* Indicates there are airborne operations in the band or US&P assignments.

Total Spectrum Usage derived from the quantitative assessments data was computed 

using NTIA’s tool with updated and validated frequency authorization data in the GMF. This 

data reflects the maximum parameters (bandwidth, power, and antenna gain) for a transmit 

station as well as the maximum geographic area over which the transmit station is authorized to 

operate. Therefore, the spectrum usage contours for each transmit or receive station, when taken 

in the aggregate, represent an upper bound on Total Spectrum Usage. Sections 3 and 4 explain 

the methods used to develop the spectrum usage contours. US&P assignments are not included 

in the spectrum usage contours since they do not have a specific geographic location but are 

taken into consideration in the frequency usage component.

1.4.2 1300-1390 MHz Band. As shown in Table 7-1 and the figures in Appendix A, 

Total Spectrum Usage on a nationwide basis in the 1300-1350 MHz and the 1350-1390 MHz 

sub-bands is significantly different. In the 1300-1350 MHz sub-band, the average number of 

transmit stations in each 5 megahertz band segment is 52. In the 1350-1390 MHz sub-band, the 

average number of transmit stations in each 5 megahertz band segment is 135. The types of 

systems operating in these two sub-bands are also different. For example, the long-range radar 

systems operated by the Federal Aviation Administration (FAA) with the Department of Defense 

(DOD) and the Department of Homeland Security (DHS) and used for Air Traffic Control (ATC) 

in the National Airspace System (NAS) defense and homeland security, primarily operate across 

the country in the 1300-1350 MHz sub-band. The DOD operates radars in this frequency range. 

The DOD operates fixed and transportable tactical radar systems, ground-based and airborne 

tactical communication systems, and airborne telemetry systems in the 1350-1390 MHz subband. Based on the results of the quantitative assessment, the heavy and diverse usage currently 

occurring in the 1300-1390 MHz band appears to limit the potential sharing opportunities. Other 

measures would be necessary in order to enable sharing in the band, including consideration of 

potential relocation of major widespread systems to other spectrum bands if feasible. A detailed 

feasibility study of the band would have to consider numerous factors beyond the results of the 

quantitative assessment.

The FAA, DOD, DHS, and Department of Commerce (DOC) operate single function 

radars in the 1300-1390 MHz and 2700-3100 MHz frequency bands. Ongoing work apart from 

the quantitative assessment initially considered combining the operational requirements of 

different single function radar systems with a multi-function phased array radar (MPAR) 
8

capability which could include various radar functions of several nationwide networks operating 

in different frequency bands, including 1300-1350 MHz and 2700-3100 MHz. Combining these 

functions is intended to effect savings of acquisition and maintenance costs without impacting 

performance, while potentially freeing up a significant geographic and spectrum footprint for 

new uses.

17 Currently, the MPAR technology demonstration has evolved into a feasibility study 

for a Spectrum Efficient National Surveillance Radar (SENSR) capability that could also include 

capabilities for national and homeland defense, whether as a single system or a system of 

systems, as part of a potential reallocation feasibility study of the 1300-1350 MHz band.

Currently, the 2700-3100 MHz frequency range is one option under consideration for potential 

relocation of the surveillance systems out of the 1300-1350 MHz band as part of the SENSR 

capability. The feasibility studies necessary to define the SENSR operational requirements, 

procurement, migration, and deployment are in the early stages. A relocation feasibility study 

has not started pending the development and approval of the study plan by impacted agencies 

and attainment of funding. 

Thus, one of several options for future feasibility studies to assess the potential 

accommodation of wireless broadband in the 1300-1390 MHz band would include making 

contiguous or non-contiguous blocks of cleared or partially cleared spectrum in the 1300-1350 

MHz sub-band available for wireless broadband if the FAA/DOD/DHS long-range radars can be 

migrated from the 1300-1390 MHz band.

The studies considering compatibility with federal systems that will not be replaced by a 

SENSR capability could first focus on the geographic areas around major cities where the

spectrum need and congestion are the greatest. To the extent practical, provisions for sharing in 

the non-federal fixed and mobile bands (e.g., 1850-2690 MHz frequency range) to accommodate 

federal systems with the ability to operate in this frequency range could be considered. The 

relocation studies could also take into account frequency and angular (azimuth angle and 

elevation angle) restrictions that the federal systems can employ to limit the impact on nonfederal operations in major cities.

Any consideration of sharing feasibility studies would also have to consider the impact of 

proposed wireless broadband systems on federal systems that would likely remain in the 1300-

1390 MHz band. 

1.4.3 1675-1695 MHz Band. As shown in Table 7-2 and the figures in Appendix B, 

Total Spectrum Usage in the 1675-1685 MHz sub-band is much less than that in the 1685-1695 

MHz sub-band. Total Spectrum Usage will be further reduced when the radiosonde receive 

stations are migrated to the 400 MHz band as shown in Table 7-3 and the figures in Appendix B. 

When the radiosonde receive stations complete their planned migration to the 400 MHz band, 

opportunities may exist to accommodate wireless broadband, contingent upon the successful 

completion of a feasibility study. The impact to non-federal users of the DOC meteorologicalsatellite data, particularly the Emergency Managers Weather Information Network (EMWIN)

users, would have to be taken into account in assessing potential sharing options with wireless 

broadband.

 

17 See NOAA, Fact Sheet: Multi-Function Phased Array Radar, available at

http://www.nssl.noaa.gov/news/factsheets/MPAR_2015.March.16.pdf.
9

1.4.4 2700-2900 MHz and 2900-3100 MHz Bands. As shown in Table 7-4 and Table 

7-5 and the figures in Appendix C and Appendix D, Total Spectrum Usage in the 2900-3100 

MHz band is much less than in the 2700-2900 MHz band. This indicates that potential sharing 

opportunities may exist in the 2900-3100 MHz band, contingent upon the successful completion 

of feasibility studies.

At this point, the affected agencies have not determined the spectrum requirements for 

the SENSR option, including how its multiple functions could be configured throughout the 

2700-3100 MHz frequency range.18 As previously noted, the feasibility studies necessary to 

define the SENSR operational requirements, procurement, migration, and deployment are in the 

early stages. The feasibility studies would also have to consider the impact of proposed wireless 

broadband systems on federal systems that would likely remain operating in the 2700-3100 MHz 

band.

1.4.5 3100-3550 MHz Band. As shown in Table 7-6 and the figures in Appendix E, 

Total Spectrum Usage is much less in the 3505-3550 MHz portion of the band as compared to 

the rest of the band. This indicates that an opportunity exists to examine the possibility of 

sharing with wireless broadband.

The 3100-3505 MHz portion of the band is used heavily on a frequency and geographic 

basis, limiting the opportunities for sharing with wireless broadband. However, as shown in 

Table 7-6, the transmit stations which are used for tactical systems operate at lower percentages 

of time as calculated using NTIA’s tool, in the range of 1 percent to 10 percent, indicating that 

opportunities for sharing on a time basis exist. To accomplish this spectrum sharing, wireless 

broadband systems would have to employ techniques that can take advantage of temporal

sharing. In the 3550-3700 MHz band, a regulatory framework is being implemented that 

requires employment of both sensing and database spectrum sharing technologies in order to 

protect DOD shipborne and ground-based radar systems.19 As experience with this innovative 

spectrum sharing approach is gained, it potentially could be implemented in portions of the 

3100-3505 MHz band for wireless broadband. Any sharing feasibility studies would also include 

consideration of airborne systems that operate in the frequency band.20

Based on experience in assessing this band in past analyses, any detailed sharing 

feasibility study would have to account for the impact to all categories of radar systems operating 

in the band (ground-based, shipborne, and airborne). In addition, radar transmitters have such 

high peak power levels that any feasibility studies in the 3100-3550 MHz band must also 

examine large signal effects on non-federal user equipment such as burnout and saturation.

21

 

18 The radars under consideration for relocation from other bands to the 2700-3100 MHz band are currently used for 

aircraft surveillance and weather sensing and include: the FAA Airport Surveillance Radar, Terminal Doppler 

Weather Radar, Air Route Surveillance Radar, and the NOAA Next-Generation Weather Radar.

19 See 47 C.F.R Part 96, Citizens Broadband Radio Service.

20 A database approach may not be practical for sharing with airborne systems. Some form of sense and avoid 

capability is an option to enable time sharing with airborne systems. Additionally, a critical component of any 

sharing approach is a practical enforcement mechanism.

21 See NTIA, An Assessment of the Near-Term Viability of Accommodating Wireless Broadband Systems in the 

1675-1710 MHz, 1755-1780 MHz, 3500-3650 MHz, and 4200-4400 MHz, 4380-4400 MHz Bands (Nov. 15, 2010), 
10

2. DESCRIPTION OF TRANSMIT AND RECEIVE STATION DATA

2.1 Introduction

This section provides a description of the transmit station and receive station data 

elements used in the quantitative assessments for the systems that were analyzed using the NTIA 

tool. The methodology for estimating time of usage for the transmit and receive stations is also 

provided.

2.2 Transmit Station Data

NTIA’s Plan for Quantitative Assessments of Spectrum Usage established metrics and 

other parameters for the quantitative assessments of the applicable bands. The data parameters 

necessary to develop an approximation of the extent to which a system uses the spectrum include

spectrum (frequency and bandwidth), geographic, and time components. NTIA provided each 

agency a list of its current frequency assignments and spectrum certifications for each band

within the GMF. Each applicable agency was requested to review, verify, update, or supplement 

the data elements contained in Table 2-1 for transmit stations operating in the bands under 

consideration in the quantitative assessments.

 

Table 2-1. Transmit Station Data Elements

Parameter Units

Frequency Megahertz

Class of Station NTIA Manual – Chapter 6

Latitude and longitude Degrees/Minutes/Seconds

Transmitter necessary bandwidth Hertz

Transmitter power Watts

Transmit mainbeam antenna gain Decibels referenced to an isotropic 

antenna

Transmit antenna height Meters

Area of operation (for mobile and transportable systems):

Radius of operation defining area of operation Kilometers

Latitudes and longitudes defining area of operation Degrees/Minutes/Seconds

Authorized state(s)/nationwide defining area of operation Annex G22

Pulse width (for pulsed systems) Microseconds

Pulse repetition rate (for pulsed systems) Pulses per second

 

(Fast Track Report) at 4-78 and Appendix G, available at

http://www.ntia.doc.gov/reports/2010/FastTrackEvaluation_11152010.pdf.

22 Annex G of the NTIA Manual contains the abbreviations used in the transmitter state/country fields of the GMF. 
11

2.3 Receive Station Data 

As stated in the NTIA Plan, each applicable agency was requested to provide the data 

elements contained in Table 2-2 for receive stations operating in the bands under consideration in 

the quantitative assessments.

Table 2-2. Receive Station Data Elements

Parameter Units

Frequency Megahertz

Class of Station NTIA Manual – Chapter 6

Latitude and longitude Degrees/Minutes/Seconds

Intermediate frequency receiver 3 dB bandwidth Hertz

Receive mainbeam antenna gain Decibel referenced to an isotropic antenna

Receive antenna gain pattern Decibel referenced to an isotropic antenna 

as a function of off-axis angle in degrees

Receive antenna height Meters

Receive antenna azimuth angle Degrees

Receive antenna minimum elevation angle Degrees

2.4 Time of Usage 

The agencies were requested to provide estimated time of use data for each transmit and 

receive station based on the guidance provided in Table 2-3.

23

Table 2-3. Guidance on Time of Use

GMF TME Field 

Entry

Description of Actual 

Use

Percentage of Time Frequency is Used 

per Day

1 Constant or nearly 

constant

50 to 100

2 Regular/frequent 10 to 50 

3 Intermittent 1 to 10 

4 Sporadic/occasional Less than 1

NTIA used the transmit station, receive station, and time of use data to compute the 

spectrum usage contours for each agency and the aggregate spectrum usage contours that are 

used to determine Total Spectrum Usage in the quantitative assessments.

 

23 There is no standardized method for federal users to collect time of use data for their spectrum dependent systems, 

and as a result these calculations serve as a first order approximation of estimated time of usage.
12

3. METHODOLOGY FOR COMPUTING TRANSMIT STATION CONTOURS

3.1 Introduction 

This section provides the methodology for computing the transmit station contours used 

in the quantitative assessments. The required propagation loss based on a generic power spectral 

density threshold was used to compute the individual transmit station contours for the systems 

analyzed using the NTIA tool. The following sections describe the methodology used for 

computing the transmit station spectrum usage contours.

3.2 Methodology for Computing Transmit Station Contours

The required propagation loss for the transmit station contour was determined using the 

following equation: 

 LRequired = [10 Log (PT) - 10 Log (BW)] + 10 Log (DC/100) + GT (θ) + GR - PSDT (3-1)

Where:

LRequired is the required terrain-dependent propagation loss (dB); 

PT is the transmitter power (Watts);

BW is the transmitter emission necessary bandwidth (Hz); 

DC is the transmitter duty cycle (percent);

GT (θ) is the transmitter antenna gain for a specific up-tilt angle (dBi); 

GR is the receiver antenna gain (dBi); and 

PSDT is the power spectral density threshold (dBW/Hz).

The frequency, transmitter necessary bandwidth, transmitter power, transmitter 

mainbeam antenna gain, and transmitter antenna height for a frequency assignment are available 

in the GMF. 

The transmitter power in the GMF is specified as peak power. The duty cycle is the 

fraction of the time that a pulsed system is in an “active” state. The duty cycle is the product of 

the pulse duration and pulse repetition rate of a pulse carrier in the GMF, equal to the percentage 

of time that the pulse power is on over a period of time. For non-pulsed signals the duty cycle is 

100 percent.

The antenna gain of the transmitter was computed based on a 1 degree up-tilt angle. A 

statistical gain antenna model is used to determine the radar antenna gain in the azimuth and 

elevation orientations.24 The model gives the antenna gain as a function of off-axis angle () for 

a given main beam antenna gain (G). The model includes separate algorithms for very high-gain 

(G > 48 dBi), high-gain (22 < G < 48 dBi), and medium-gain (10 < G < 22 dBi) antennas. 

Figure 3-1 illustrates the general form of the antenna gain distribution. The equations for the 

 

24

 National Telecommunications and Information Administration, NTIA Technical Memorandum 09-461, 

Description of a Model to Compute the Aggregate Interference from Radio Local Area Networks Employing 

Dynamic Frequency Selection to Radars Operating in the 5 GHz Frequency Range (May 2009) at 4-2. 
13

angles M (first side-lobe region), R (near side-lobe region), and B (far side-lobe region) are 

given in Table 3-1. The antenna gains, as a function of off-axis angle, are given in Table 3-2 for 

very high-gain antennas, in Table 3-3 for high-gain antennas, and in Table 3-4 for medium-gain 

antennas. The angle  is in degrees and all gain values are given in terms of decibels relative to 

an isotropic antenna (dBi).

Figure 3-1. General Form of Antenna-Gain Distribution

Table 3-1. Angle Definitions

Very high-gain

(G > 48 dBi)

High-gain

(22 < G < 48 dBi)

Medium-gain

(10 < G < 22 dBi)

M = 50 (0.25 G + 7)0.5/10G/20

R = 27.466 10–0.3G/10

B = 48

M = 50 (0.25 G + 7)0.5/10G/20

R = 250/10G/20

B = 48

M = 50 (0.25 G + 7)0.5/10G/20

R = 250/10G/20

B = 131.8257 10–G/50

Table 3-2. Equations for Very High-Gain Antennas (G > 48 dBi)

Angular interval (degrees) Gain (dBi)

0 to M

M to R

R to B

B to 180

G - 4 × 10–4(10G/10) 

2

0.75 G - 7

29 - 25 log ()

-13

Table 3-3. Equations for High-Gain Antennas (22 < G < 48 dBi)

Angular interval (degrees) Gain (dBi)

0 to M

M to R

R to B

B to 180

G - 4 × 10–4(10G/10) 

2

0.75 G - 7

53 - (G/2) - 25 log ()

11 - G/2
14

Table 3-4. Equations for Medium-Gain Antennas (10 < G < 22 dBi)

Angular interval (degrees) Gain (dBi)

0 to M

M to R

R to B

B to 180

G - 4 × 10–4(10G/10) 

2

0.75 G - 7

53 - (G/2) - 25 log ()

0

For transmitter antenna gain values of less than 10 dBi, the mainbeam antenna gain 

specified in the GMF frequency assignment was used to compute the transmit station contour. 

The transmit station contours were computed for a receive antenna gain of 0 dBi and height of 2 

meters. 

The propagation loss used to compute the transmit station contour is based on a terraindependent model. The Irregular Terrain Model (ITM) in the Point-to-Point Mode was used for 

computing the propagation loss for the transmit station contours.25 Since the Point-to-Point 

Mode uses actual terrain data, it will provide a better estimate of the propagation loss.26 The 

statistical and environmental parameters used with the actual terrain profiles in calculating 

propagation loss are shown in Table 3-5.

Table 3-5. Transmit Station ITM Point-to-Point Mode Parameters

Parameter Value

Mode Single Message

Surface Refractivity 301 N-units

Conductivity of Ground 0.005 S/M

Dielectric Constant of Ground 15

Polarization Vertical

Reliabilitya50 percent

Confidencea50 percent

Frequency Variable 

Transmitter Antenna Height Variable

Receiver Antenna Height 2 meters27

Radio Climate Continental Temperate

Terrain Database United States Geological Survey - 3 Second

Note a: The reliability and confidence percentages used in generating the transmit station 

contours do not take into account anomalous propagation effects (e.g., ducting conditions)

For transmit station contours, the PSD threshold was determined based on a 1 dB 

increase in the receiver thermal noise density of -204 dBW/Hz. The 1 dB increase results in an 

interference-to-noise density ratio of -6 dB. The PSD threshold used to compute the transmit 

station contour was -210 dBW/Hz.

 

25 See NTIA Report 82-100, A Guide to the Use of the ITS Irregular Terrain Model in the Area Prediction Mode

(April 1982).

26 ITM in the Point-to-Point mode takes into account terrain but does not include local clutter (e.g., buildings).

27 An antenna height of 2 meters is the minimum value that can be used in the ITM propagation model. 
15

The technical parameters that affect the size of the transmit station contours include: the 

PSD threshold, receive antenna height, antenna model, propagation model, and other losses (e.g., 

clutter).

28

 The selection of the technical parameters used in the quantitative assessments is

intended to be technology neutral. The selection of other technical parameters could affect the 

size of the transmit station contours. These technical parameters can be refined when the more 

detailed feasibility studies are performed to assess potential sharing opportunities with a specific 

technology.

NTIA authorizes transmit stations for terrestrial and airborne systems that operate across 

large areas such as statewide, regional, in the conterminous United States, or the entire United 

States and Possessions (US&P). Spectrum usage contours were not generated for these transmit 

stations; however, they were included in the frequency and time usage component of Total 

Spectrum Usage.

29

Transmit station contours were not computed for meteorological-satellite downlink and 

radiosonde airborne transmitters due to the relatively low received signal levels at the surface of 

the Earth.30 For assessing spectrum usage, it was deemed more appropriate to compute spectrum 

usage contours for the meteorological-satellite and radiosonde receive stations as discussed in 

Section 4. 

3.2.1 Fixed Transmit Station Contour. The transmit station latitude and longitude was 

used as the center point for the contour. The ITM terrain dependent propagation loss satisfying 

the required propagation loss values from Equation 3-1 was used to determine the transmit 

station contour. A terrain profile was generated at each 1 degree increment around a transmit 

station location. Using the computed values of required propagation loss in Equation 3-1, the 

point farthest away along the terrain profile corresponding to the required propagation loss is 

used to determine the transmit station contour distance.

3.2.2 Transportable Transmit Station Contour. The area of operation for a 

transportable transmit station in the GMF was described in terms of: 1) a circle with a latitude 

and longitude as the center point and a radius of operation; or 2) a rectangle with the latitude and 

longitude specifying the northeast and southwest corner. In both cases, multiple transmit 

contours were generated along the edge of the circle/rectangle. The multiple transmit contours 

were combined to generate a composite transmit contour around the area of operation.31 Taking 

the convex hull of the composite transmit contour generally results in a smoother-shaped 

polygon, because the points creating concave angles was removed.

 

28 Building clutter losses were not included in the generation of the transmit station contours shown in the 

appendices.

29 The feasibility studies to assess the potential sharing or relocation opportunities will take into account federal 

US&P operations.

30 Fast Track Report at 4-9 and Appendix C.

31 Graham, R.L. (1972). An Efficient Algorithm for Determining the Convex Hull of a Finite Planar Set, Information 

Processing Letters 1, 132-133.
16

3.2.3 Shipborne Transmit Station Contour. For the shipborne transmit stations, a ship 

was moved along the coast in 10 kilometer (km) increments. The ship was positioned 10 km off 

shore. The ITM path started at 475 km inland then stepped in 10 km increments toward the 

shore until the PSD threshold was crossed. This was performed with a ± 20 degrees sweeping 

angle perpendicular to the shore. The angle sweep was in 2 degree steps from -20 degrees to +20 

degrees. Using the computed values of required propagation loss, the point farthest in-land along 

the terrain profile corresponding to the required propagation loss was used to determine the 

transmit station contour distance. The shipborne transmit contour will encompass the full length 

of the shoreline off of which the shipborne system operates as specified in the GMF (e.g., East, 

West, or Gulf coast). 

3.2.4 Airborne Transmit Station Contour. For the airborne stations, the area of 

operation specified in the GMF frequency authorization was used to represent the transmit 

station contour.
17

4. METHODOLOGY FOR COMPUTING RECEIVE STATION CONTOURS

4.1 Introduction

This section provides the methodology for computing the receive station contours used in 

the quantitative assessments. The methodology described in this section was used for 

meteorological-satellite, radiosonde, and nuclear detonation detection receive stations. The 

required propagation loss based on a generic power spectral density threshold was used to 

compute the individual receive station contours. The following sections describe the 

methodology used for computing the receive station spectrum usage contours. 

4.2 Methodology for Computing Receive Station Contours

The required propagation loss for the receive station contour was determined using

Equation 4-1. 

 LRequired (φ) = [EIRP - 60] + GR (φ) - PSDT (4-1)

Where:

LRequired (φ) is the required terrain-dependent propagation loss as a function of the off-axis 

angle (dB); 

EIRP is the transmitter equivalent isotropically radiated power (dBW);

GR (φ) is the receive antenna gain as a function of off-axis angle (dBi); and 

PSDT is the power spectral density threshold (dBW/Hz).

The receive station contours were computed for a transmitter EIRP of 0 dBW and 

antenna height of 2 meters. The emission bandwidth used in computing the receive station 

contours was 1 megahertz.32 

Signals from polar orbiting satellites can be received at any azimuth so the mainbeam 

was rotated 360 degrees in azimuth at the minimum elevation angle. For geostationary satellites,

signals are received at a specific elevation angle and azimuth angle. The receive antenna gain 

associated with the mainbeam region and the off-mainbeam region was used in the calculation of 

the receive station contour. The antenna model for the meteorological-satellite receive Earth 

stations was based on Recommendation ITU-R F.1245-1.33 In cases where the ratio between the 

antenna diameter and the wavelength is greater than 100 (D/λ > 100), the following equations 

were used:

 

32

 A 1 megahertz reference bandwidth is commonly used for Federal Communications Commission emission 

standards for commercial services. The 60 dB in Equation 4-1 is determined by taking 10 Log (1x106).

33

 Recommendation ITU-R F.1245-1, Mathematical Model of Average or Related Radiation Patterns for Line-ofSight Point-to-Point Radio Relay System Antenna for Use in Certain Coordination Studies and Interference 

Assessment in the Frequency Range from 1 GHz to About 70 GHz (2000).
18

G(φ) = Gmax – 2.5x10-3((D/λ) φ)2for 0° < φ < φm (4-2)

G(φ) = G1 for φm ≤ φ < max (φm, φr) (4-3)

G(φ) = 29 – 25 Log (φ) for max (φm, φr) ≤ φ < 48° (4-4)

G(φ) = -13 for 48° ≤ φ ≤ 180° (4-5)

Where:

Gmax: Maximum antenna gain (dBi) 

G(): Gain relative to an isotropic antenna (dBi)

: Off-axis angle (degrees)

D: Antenna diameter (m) 

 Wavelength (m)

G1: Gain of the first side lobe = 2 + 15 log (D/)

φm = (20 λ)/D (Gmax – G1)

0.5 degrees (4-6)

φr = 12.02 (D/λ)-0.6 degrees (4-7)

In cases where the ratio between the antenna diameter and the wavelength is less than or equal to 

100 (D/λ ≤ 100), the following equations were used:

G(φ) = Gmax – 2.5x10-3((D/λ) φ)2for 0° < φ < φm (4-8)

G(φ) = 39 – 5 Log (D/λ) - 25 Log (φ) for φm≤ φ < 48° (4-9)

G(φ) = -3 - 5 Log (D/λ) for 48° ≤ φ ≤ 180° (4-10)

D/ is estimated using the following expression:

20 Log (D/λ) ≈ Gmax - 7.7 (4-11)

Where:

Gmax: Maximum antenna gain (dBi)

The antenna pattern for a 43 dBi mainbeam antenna gain is shown in Figure 4-1.
19

Figure 4-1. Azimuth and Elevation Antenna Pattern

For radiosonde receive antennas, the statistical gain antenna model described in Tables 3-

1 through 3-4 was used. A 5 degree up-tilt angle was used to compute the off-axis antenna 

gain.34

The propagation loss used to compute the receive station contours in the quantitative 

assessments was based on a terrain-dependent model. ITM in the Point-to-Point Mode was used 

for computing the propagation loss for the receive station contours. Since the Point-to-Point 

Mode uses actual terrain data, it will provide a better estimate of the propagation loss. The 

statistical and environmental parameters used with the actual terrain profiles in calculating 

propagation loss are shown in Table 4-1.

Table 4-1. Receive Station ITM Point-to-Point Mode Parameters

Parameter Value

Mode Single Message

Surface Refractivity 301 N-units

Conductivity of Ground 0.005 S/M

Dielectric Constant of Ground 15

Polarization Vertical

Reliabilitya10 percent

Confidencea10 percent

Frequency Variable

Transmitter Antenna Height 2 meters35

Receiver Antenna Height Variable

Radio Climate Continental Temperate

Terrain Database United States Geological Survey - 3 Second

Note a: The reliability and confidence percentages used in generating the receive station 

contours do not take into account anomalous propagation effects (e.g., ducting conditions)

 

34 When flights are at maximum range, radiosonde receive antennas can track down to the horizon.

35 An antenna height of 2 meters is the minimum value that can be used in the ITM propagation model. 
20

For receiving stations, the PSD threshold was determined based on a 0.5 dB increase in 

the receiver thermal noise density of -204 dBW/Hz. The 0.5 dB increase results in an 

interference-to-noise density ratio of -9 dB. The PSD threshold used to compute the receive 

station contour in the quantitative assessments was -213 dBW/Hz.

The technical parameters that affect the size of the receive station contours include: the 

PSD threshold, transmit antenna height, antenna model, propagation model, and other losses 

(e.g., building blockage). The selection of the technical parameters used in the quantitative 

assessments was intended to be technology neutral. The selection of other technical parameters 

would affect the size of the receive station contours. These technical parameters can be refined 

when the more detailed compatibility studies are performed to assess potential sharing 

opportunities with a specific technology.

The receive station latitude and longitude is used as the center point for the contour. The 

ITM terrain dependent propagation loss satisfying the required propagation loss values from 

Equation 4-1 was used to determine the receiver station contour. At each 1 degree increment 

around a receive station location, a terrain profile was generated. Using the computed values of 

required propagation loss in Equation 4-1, the point farthest away along the terrain profile 

corresponding to the required propagation loss was used to determine the receive station contour 

distance. 

The mainbeam of a receive station is pointed at a fixed azimuth angle and a fixed

elevation angle is taken into account when computing the contour. Because of the directivity of 

the receive antenna, a “keyhole” concept may be used to compute the receive contour. The 

keyhole concept takes into account the larger distance along the mainbeam (keyhole region) of a 

receive antenna. It then follows that the region outside the keyhole region (the area off the 

mainbeam) requires smaller distances as shown in Figure 4-2. The specific numerical figures for 

the distances associated with the keyhole regions and off-mainbeam regions depend on the 

specific type(s) of receive antennas. 

Figure 4-2. Example of Keyhole Receive Station Contour
21

4.3 Radio Astronomy Observatories

As specified in footnote US385, of the U.S. Table of Frequency Allocations the radio 

astronomy observatories listed in Table 4-2 operate in the 1350-1400 MHz band on an 

unprotected basis.

Table 4-2. Radio Astronomy Observatories in the 1350-1400 MHz Band

Location Geographical Area

Hat Creek, CA Rectangle between latitudes 40° 00' N and 42° 00' N and between longitudes 

120° 15' W and 122° 15' W

Goldstone, CA 80 kilometer radius centered on 35° 20' N, 116° 53' W

Arecibo, PR Rectangle between latitudes 17° 30' N and 19° 00' N and between longitudes 

65° 10' W and 68° 00' W

Socorro, NM Rectangle between latitudes 32° 30' N and 35° 30' N and between longitudes 

106° 00' W and 109° 00' W

Green Bank, WV Rectangle between latitudes 37° 30' N and 39° 15' N and 

between longitudes 78° 30' W and 80° 30' W

Brewster, WA 80 kilometer radius centered on 48° 08' N, 119° 41' W

Fort Davis, TX 80 kilometer radius centered on 30° 38' N, 103° 57' W

Hancock, NH 80 kilometer radius centered on 42° 56' N, 71° 59' W

Kitts Peak, AZ 80 kilometer radius centered on 31° 57' N, 111° 37' W

Los Alamos, NM 80 kilometer radius centered on 35° 47' N, 106° 15' W

Mauna Kea, HI 80 kilometer radius centered on 19° 48' N, 155° 27' W

North Liberty, IA 80 kilometer radius centered on 41° 46' N, 91° 34' W

Owens Valley, CA 80 kilometer radius centered on 37° 14' N, 118° 17' W

Pie Town, NM 80 kilometer radius centered on 34° 18' N, 108° 07' W

Saint Croix, VI 80 kilometer radius centered on 17° 45' N, 64° 35' W

Big Pine, CA Two contiguous rectangles, one between latitudes 36° 00' N and 37° 00' N 

and between longitudes 117° 40' W and 118° 30' W and the second between 

latitudes 37° 00' N and 38° 00' N and between longitudes 118° 00' W and 

118° 50' W

The geographical areas specified in Table 4-2 was be used to generate spectrum usage 

contours for the radio astronomy observatories.
22

5. PERCENTAGE OF POPULATION IMPACTED AND GEOGRAPHIC 

AVAILABILITY CALCULATIONS

5.1 Introduction

This section provides a description of how the estimated percentage of population 

impacted and the percentage of geographic availability values were computed for the transmit 

station and receive station spectrum usage contours in the quantitative assessments.

5.2 Percentage of Population Impacted Calculation

The population data is based on the 2015 U.S. Census data. The population centers and 

their corresponding coordinates and population counts were downloaded from the Centers of 

Population by Census Tract link at https://www.census.gov/geo/reference/centersofpop.html.

36

The population impacted for a given spectrum usage contour is determined by finding all 

of the Census tracts that fall within the transmit station or receive station spectrum usage 

contours, then summing the total population within those tracts. The percentage of the 

population impacted is determined by dividing the summation of population in the Census tracts 

that fall within the spectrum usage contours by the total U.S. population from the 2010 Census.

5.3 Percentage of Geographical Availability Calculation

The percentage of geographic availability represents the area as a percentage of the

contiguous United States that was geographically untouched by the spectrum usage contours. 

Geographical availability does not take into account US&P frequency assignments which can 

operate inside or outside of the spectrum usage contours. A spectrum usage contour is denoted 

as a polygon Rn and the set of spectrum usage contours was queried by frequency and a search 

radius that encompasses all of the contiguous United States. The contiguous United States was 

defined as a polygon denoted as S.

37

 The percentage of geographic availability calculation is 

described below.

The union set of aggregate spectrum usage contour polygons was calculated using 

Equation 5-1.

Cu = R1 ∪ R2 ∪ R3 ∪ ... (5-1)

 

36 Census tracts are statistical subdivisions of a county or equivalent entity that are updated prior to each decennial 

census as part of the Census Bureau’s Participant Statistical Areas Program. Census tract boundaries are updated 

every 10 years and are based on the decennial census. In this analysis the files dated 2015 are being used. The 

information on census tracts is available on the Census website: 

https://ask.census.gov/faq.php?id=5000&faqId=10472.

37 The polygon for the United States is available at https://www.census.gov/geo/maps-data/data/cbf/cbf_nation.html.
23

Equation 5-1 represents the total area covered by the spectrum usage contours.

The set difference of the United States polygon and the union of the spectrum usage 

contour polygons were calculated using Equation 5-2.

S - Cu (5-2)

Equation 5-2 represents the total areas of the contiguous United States that were not 

covered by the spectrum usage contours.

The areas of S - Cu and S were computed using the area of a polygon on a sphere shown 

below:38

R

2 ∑ [(λk+2 - λk) sin (φk+1)]/2 (5-3)

The indexing for the summation is performed from k = 1 to n. The parameters φk and λk

represent latitudes and longitudes respectively of the k

th coordinates that define the boundary of 

the polygon, and n + 1 and n + 2 wrap around so that λn+1 = λ1 and similarly for λn+2 = λ2. The 

same indexing holds for φ. The radius of the Earth in meters is R.

If S - Cu is complex, meaning a polygon or multi-set of polygons with holes, use the area 

of a polygon on a sphere to subtract the area from internal “hole polygons” using Equation 5-4 as 

shown in Figure 5-1.

Figure 5-1. Calculation of Geographic Availability

Area (S - Cu) = Area (A) – Area (B) + Area (C) (5-4)

The percentage of the area of geographic availability was computed as shown in Equation 

5-5.

[Area (S - Cu)/Area(S)] x 100 (5-5)

 

38 National Aeronautics and Space Administration, Jet Propulsion Laboratory, JPL Publication 07-3, Some 

Algorithms for Polygons on a Sphere (June 2007) at 7, available at http://trsnew.jpl.nasa.gov/dspace/handle/2014/40409.

A

B C
24

6. OVERVIEW OF FEDERAL OPERATIONS 

6.1 Introduction

This section provides an overview of the federal operations in the 1300-1390 MHz, 1675-

1695 MHz, 2700-2900 MHz, 2900-3100, and 3100-3550 MHz bands. 

6.2 Overview of Federal Systems

Table 6-1 shows the federal agencies that have frequency assignments for systems that 

operate in the quantitative assessment bands.

Table 6-1. Federal Agencies Operating in Quantitative Assessment Bands 

Quantitative Assessment 

Frequency Band (MHz)

Federal Agencies with Frequency Assignments in the 

Quantitative Assessment Frequency Band

1300-1390 AF, AR, DHS, DOC, FAA, MC, N, NASA, USCG

1675-1695 AF, AR, DOC, MC, N, NASA

2700-2900 AF, AR, DOC, DOE, FAA, MC, N, NASA

2900-3100 AF, AR, USCG, DHS, DOC, DOE, FAA, N, NASA, DOT

3100-3550 AF, AR, N, MC

The following paragraphs provide an overview of the federal operations in bands under 

consideration in the quantitative assessment. A more detailed description of the federal 

operations in these bands is provided at www.spectrum.gov.

6.2.1 1300-1390 MHz Band. The 1300-1390 MHz band is comprised of two subbands: 1300-1350 MHz and 1350-1390 MHz. The 1300-1350 MHz sub-band is allocated on a 

primary basis for the federal aeronautical radionavigation service with a secondary allocation for 

the radiolocation service. The 1350-1390 MHz sub-band is allocated on a primary basis for the 

federal radiolocation, fixed, and mobile services. 

The predominant federal systems operating in the 1300-1350 MHz frequency range are 

the long-range radar systems operated to support ATC in the NAS, border surveillance, early 

warning missile detection, and drug interdiction.

39

 The allocation for the aeronautical 

radionavigation service ends at 1350 MHz, limiting the operation of the long-range radars by the 

FAA to the 1300-1350 MHz sub-band.40 The long-range air surveillance radars operate as a joint 

activity of the FAA, DOD, and DHS via frequency authorizations held by the FAA. The radars 

support ATC, defense and homeland security missions. The data from the long-range radar 

 

39 Long-range radars are operated in this portion of the radio frequency spectrum because the effects of rain and fog 

on radar target detection are very low, the external background noise levels are low, and high-power transmitter 

tubes operate very efficiently. These factors are important to achieve the long-range detection of different size 

aircraft as well as other targets. 

40 As specified in international footnote 5.334, in Canada and the United States, the 1350-1370 MHz band is 

allocated to the aeronautical radionavigation service on a primary basis.
25

systems is also used by the DOD, DHS, and Department of Energy (DOE) in performing their 

missions. 

There is a large diversity in the types of systems that operate in the 1350-1390 MHz 

portion of the band compared to the 1300-1350 MHz portion. While the FAA operates a small 

number of long-range radars in the 1350-1390 MHz portion of the band, the DOD (Air Force, 

Army, Marine Corps, and Navy) is the predominant user. The types of systems operated by the 

DOD include: fixed and transportable high-power tactical radar systems, transportable tactical 

communication systems, vehicular and portable communication systems, aeronautical telemetry 

systems, tactical air-to-ground communications systems, and airborne test and training systems. 

NASA and DHS operate a limited number of radar systems in the band. The DOD operates the 

Nuclear Detonation Detection System (NDS) in the 1378.55-1383.55 MHz band segment.

41

 

There are also radio astronomy sites operating in the 1350-1390 MHz portion of the band on an 

unprotected basis. 

The fixed and transportable radar systems operating in the 1300-1390 MHz band are 

characterized by high-power transmitted signals and high gain antennas. The radar antennas 

rotate 360 degrees, radiating in all directions around the location of the radar. The transportable 

tactical radar and communication systems can be authorized to operate over a large geographic 

area (e.g., radius of operation in excess of 100 kilometers) employing antennas that can be 

pointing in any direction. The combination of high transmitted power, high antenna gain, and 

large operational areas results in significant geographic areas where there are high signal levels 

that can be received by other terrestrial users operating in the band. 

6.2.2 1675-1695 MHz Band. The 1675-1695 MHz band is allocated on a primary 

basis to federal and non-federal meteorological aids (radiosondes) and meteorological-satellite 

(space-to-Earth) services.

42

 The DOC Geostationary Operational Environmental Satellites 

(GOES) series of satellites operate in this band, transmitting weather and other meteorological

data to earth station receivers for further processing and distribution. Non-federal entities such 

as universities, private sector weather forecasters, and others also employ receive-only stations 

for reception of meteorological-satellite service downlink transmissions. The DOC GOES 

meteorological data is also transmitted directly to federal and non-federal end-users. 

For the GOES-Legacy, there are certain signals such as GOES VARiable (GVAR), multiuse data link (MDL), and Sensor Data (SD) in the 1675-1695 MHz frequency band. The overall 

bandwidth requirement for all GOES-R links in this band are approximately the same as GOESLegacy links although GOES-R links provide significantly more data by using more efficient 

techniques. GOES-NEXT (Next Generation) will have an increase in total bandwidth 

requirements in the 1675-1695 MHz band. GOES-R has a different frequency distribution than 

GOES-Legacy. DOC recently modified the design for the GOES-R,S,T,U Data Collection 

Platform Reports (DCPR) system to accommodate Advanced Wireless Service-3 sharing in 

1695-1710 MHz. While the original design included 400 kHz channels centered on 1694.5 MHz 

and 1694.8 MHz, the DCPR will now operate from 1679.7 to 1680.4 MHz, relaying near-real 

 

41 The purpose of the NDS is to broadcast nuclear detonation data to a variety of fixed and mobile stations.

42 The 1675-1695 MHz band is used internationally for environmental sensing.
26

time hemisphere data from approximately 27,000 data collection platforms (DCP). DCPRs are 

used to manage water use and predict flooding, for Tsunami warning facilities, and for up to 

about 4,000 Remote Automatic Weather Stations (RAWS) which largely address rural 

firefighting. The total cost, including launch vehicles, for the GOES-R Satellite Program is $8.5 

billion in current year dollars and the current procurement schedule would result in October 2016 

satellite launch. GOES-NEXT will require emissions in the 1676-1692 MHz band to meet high 

resolution requirements for GOES Rebroadcast (GRB) and DCPR signals. 

The DCPR transponder is a bent-pipe, receiving signals from the DCPs in 401.7-402.4 

MHz, and then downlinked in the 1675-1695 MHz band. End users are composed of many 

federal, state, and local agencies required to monitor environmental and earth resources for a 

variety of purposes, that include: meteorological analysis and forecasting, river forecast, tsunami 

warnings, flood warnings, reservoir management, dam monitoring, water quality monitoring, fire 

potential, navigation, irrigation control, seismic monitoring, and other highly variable 

phenomena where observations must be collected frequently and in real-time. The bandwidth 

requirements for this signal have remained the same in comparison to the comparable function of 

the previous generation of GOES missions.

The GRB on GOES-R replaces the current GVAR system and provides users with a 

variety of enhanced data and products at a much higher data rate (approximately 31 megabytes 

per second as compared to the current data rate of 2.11 megabytes per second), including a 

stream of GOES-R processed instrument data, other DOC products, and related information to 

the weather research and earth sciences community. The GRB signal is downlinked in the 1675-

1695 MHz band. This signal requires an increase in the bandwidth in comparison to the 

comparable function of the previous generation of GOES missions.

The GOES telemetry and command subsystem provides the functional interface between 

the spacecraft and ground command and control. It is composed of both radio frequency and 

digital (baseband) segments. Telemetry parameters describing the status, configuration, and 

health of the spacecraft payload and subsystems are downlinked to the Command and Data 

Acquisition (CDA) station and sent to the Satellite Operations Center. Commands are received 

onboard the spacecraft in another frequency band for controlling mission operations and 

managing expendable resources. This signal is downlinked in the 1675-1695 MHz band. The 

bandwidth requirements for this signal have decreased in comparison to the comparable function

of the previous generation of GOES missions.

 

The EMWIN is designed to provide vital data to the nation’s emergency management 

community. The DOC provides a broadcast of live weather and civil emergency information to 

computers across the United States, the Caribbean, South America, and over most of the Pacific 

and Atlantic Oceans. EMWIN has been made available by the DOC in cooperation with the 

National Environmental Satellite Data and Information Service (NESDIS) since 1995. The 

EMWIN delivers weather warnings in all weather conditions. The EMWIN system’s primary 

use is warning products and other processed data (graphics and imagery) that are needed by 

emergency managers. EMWIN’s flexibility and low cost allows it to be used by even small 

emergency management units anywhere in the United States. The EMWIN signal is transmitted 

from GOES satellites using the 1675-1695 MHz band. The EMWIN signal requires an increase 
27

in the bandwidth in comparison to the comparable function of the previous generation of GOES 

missions.

The High Rate Information Transmission (HRIT) is an enhanced replacement of the 

current Low Rate Information Transmission on the current GOES satellites and will be initiated 

on GOES-R. The data rate will be 400 kilobytes per second instead of the current 256 kilobytes 

per second. The HRIT signal is transmitted in the 1675-1695 MHz band. The HRIT signal 

requires an increase in the bandwidth requirements in comparison to the comparable function of 

the previous generation of GOES missions.

The GOES-R and GOES-NEXT will provide continuous coverage (24 hours per day and 

7 days a week).43 Table 6-2 and Table 6-3 provide information on both GOES-R and GOESNEXT frequency and bandwidth requirements and any changes associated with the link. The 

main earth stations planned for GOES-R geographic coverage includes sites located at Wallops, 

VA; Fairmont, WV; and Suitland, MD. The differences between planned systems and current 

GOES-Legacy systems are a change in the back up locations from Greenbelt, MD and Fairbanks, 

AK to Fairmont, WV.

Table 6-2. DOC GOES-R Spectrum Usage in 1675-1695 MHz Band

Lower 

Frequency

(MHz)

Upper 

Frequency

(MHz)

Frequency Change

GOES-Legacy to GOES-R

(MHz)

Bandwidth Change

GOES-Legacy to GOES-R

(MHz)

Link Purpose

1679.7 1680.1 1694.5 to 1679.9 No Change DCPR 

Domestic

1680 1680.4 1694.8 to 1680.2 No Change DCPR 

International

1681.705 1691.495 1685.7 to 1686.6 Increase from 4.22 (GVAR) 

to 9.79

GRB

1681.15 1692.05 1685.7 to 1686.6 Increase from 4.22 (GVAR) 

to 10.9

GRB

1692.996 1693.004 1694 to 1693 Decrease from 0.016 to 

0.008

Telemetry to 

CDA

1693.495 1694.705 1692.7 to 1694.1 Increase from 0.027 to 1.21 HRIT/EMWIN

Table 6-3. DOC GOES-NEXT Spectrum Usage in 1675-1695 MHz Band

Lower 

Frequency

(MHz)

Upper 

Frequency

(MHz)

Frequency Change

GOES-R to 

GOES-NEXT

(MHz)

Bandwidth Change

GOES-R to 

GOES-NEXT

(MHz)

Link Purpose

1675.05 1675.45 1679.9 to 1675.25 No Change DCPR

1675.35 1675.75 1680.2 to 1675.55 No Change DCPR

1676 1692 1686.6 to 1684 Increase from

9.79/10.9 to 16

GRB

1692.996 1693.004 1693 to 1693 No Change Telemetry to 

 

43 A Stage 4 (operational) spectrum certification review has been granted for GOES-R. GOES-NEXT has a Stage 1 

(conceptual) spectrum certification.
28

CDA

1693.5 1694.85 1694.1 to 1694.1 Increase from 

1.21 to 1.5

HRIT/EMWIN

The federal agencies use the 1675-1683 MHz portion of the band to transmit 

meteorological data from radiosondes to ground stations for weather forecasting. Radiosondes 

are small, expendable instrument packages carried aloft by a weather balloon. Radiosondes 

operate in the Meteorological Aids service providing atmospheric observation data essential for 

weather forecasting and research. The DOC releases about 70,000 radiosondes each year at 92 

observation stations throughout the United States and its territories. The 400.15-406 MHz and 

the 1675-1683 MHz bands are both allocated and used for radiosonde meteorological aids

operations. The DOC is in the process of relocating radiosonde systems operating in the 1675-

1683 MHz frequency range to the 400.15-406 MHz frequency range. The DOC will expand the 

use of radiosondes operating in the frequency range 400.15-406 MHz, and not require use of the 

1675-1683 MHz band in the future. Radiosonde operations are critical to the DOC mission; 

therefore, harmful interference in the 400.15-406 MHz frequency band could impact the DOC 

mission to understand and predict changes in climate and weather. Radiosondes will continue 

operating in the 1675-1680 MHz portion of the band until the transition to 400 MHz is 

completed in 2021.

6.2.3 2700-2900 MHz Band. The 2700-2900 MHz band is allocated on a primary 

basis for the federal meteorological aids service and aeronautical radionavigation service, and on 

a secondary basis for the federal radiolocation service. The 2700-2900 MHz band is used by 

federal agencies for operating various types of radar systems that perform missions critical to 

safe and reliable ATC and accurate weather monitoring in the United States. This includes 

airport surveillance radar (ASR) systems and meteorological radars. The ASR systems are 

operated by the FAA and the DOD to monitor national airspace for cooperative and noncooperative targets in and around airports.44

 The ASRs also can have some limited weather 

monitoring functions. A network of Next Generation Radar (NEXRAD) systems are operated by 

the DOC in the band 2700-2900 MHz that provide quantitative and automated real-time 

information on storms, precipitation, hurricanes, and other important weather information 

(rainfall amounts and rates, wind velocity, wind direction, hail, snow) with higher spatial and 

temporal resolution than previous weather radar systems. The NEXRAD systems are operated 

throughout the United States by DOC, FAA, and DOD. All of the radar systems operating in this 

band have tuning capabilities; however, any re-tuning effort would require replacement 

components with new technology.45 Apart from the quantitative assessment, the 2700-3100 

MHz frequency range is under consideration as a target for potential relocation of surveillance 

capabilities from various bands, including1300-1350 MHz, as part of the SENSR program. The 

DOD operates the tactical equivalent of the FAA ASR in the band. The ASR and NEXRAD 

systems operate at fixed locations. The DOD tactical ATC radar systems operate at fixed 

locations or are transportable operating over a specified geographic area.

 

44 The ASR (also referred to as terminal radars) systems in the 2700-2900 MHz band are used for control of aircraft 

during departure and landing.

45

 For NEXRAD, retuning requires contracting efforts for engineering and production of replacement tuning 

components.
29

The radars operating in the 2700-2900 MHz band are characterized by high-power 

transmitted signals and high gain antennas. The radar antennas rotate 360 degrees, radiating in 

all directions around the location of the radar. The combination of high transmitted power and 

high antenna gain results in large geographic areas where there are high signal levels that can be 

received by other terrestrial users operating in the band. The transportable operation of the DOD 

radars can also impact sharing with other terrestrial users over large geographic areas.

6.2.4 2900-3100 MHz Band. The 2900-3100 MHz band is allocated on a primary 

basis for the federal radiolocation service and on a secondary basis for the non-federal 

radiolocation service. The band is also allocated on a primary basis for the federal and nonfederal maritime radionavigation service. The federal agencies use the 2900-3100 MHz band for 

operating various types of radar systems that perform missions critical to safe and reliable 

maritime navigation and accurate weather monitoring in the United States. Federal and 

commercial vessels operate radar systems and positioning aids in this band for maritime 

radionavigation for the safe transportation of people and goods, and to facilitate the flow of 

commerce. The DOD operates tactical ATC, artillery and rocket tracking, air search and 

surveillance, and range safety radars in the 2900-3100 MHz band. 

The DOC NEXRAD system uses this band when operation in the 2700-2900 MHz band 

is not possible due to spectrum congestion. Apart from this quantitative assessment, the 2700-

3100 MHz frequency range is under consideration as a target for potential relocation of 

surveillance capabilities from various bands, including 1300-1350 MHz, as part of the SENSR 

program.

The Navy, Department of Transportation’s (DOT) Saint Lawrence Seaway Development 

Corporation (SLSDC) and Maritime Administration (MARAD), and United States Coast Guard 

(USCG) operate navigation radar systems and positioning aids in the 2900-3100 MHz band. The 

USCG and SLSDC Radar Beacon (RACON) systems that work with shipborne navigation radars 

to electronically identify maritime obstructions and navigation points operate in this band. 

RACON systems are used to identify navigation hazards to ships traveling, for example, along 

the Saint Lawrence Seaway.46 

The radar systems operating in this band are characterized by high-power transmitted 

signals and high gain antennas. The radar antennas rotate 360 degrees, radiating in all directions 

around the location of the radar. The transportable tactical radar systems can be authorized to 

operate over a large geographic area (e.g., radius of operation in excess of 100 kilometers) 

employing antennas that can be pointing in any direction. The shipborne radars can operate 

anywhere along the coast and in-land waterways. The combination of high transmitted power, 

high antenna gain, and the large operational areas results in significant geographic areas where 

there are high signal levels that can be received by other terrestrial users operating in the band. 

6.2.5 3100-3550 MHz Band. The 3100-3550 MHz band is allocated on a primary basis 

for the federal radiolocation service and on a secondary basis for the non-federal radiolocation 

 

46 See DOT, Economic Impacts of the Great Lakes-St. Lawrence Seaway (2011), available at

http://www.seaway.dot.gov/publications/economic-impact-study-0 (highlighting the economic importance of this 

waterway to the U.S. economy).
30

service. There are also secondary allocations for federal and non-federal Earth explorationsatellite (active) and space research (active) services. The DOD operates high-powered air 

defense radar systems on fixed, mobile, shipborne, and airborne platforms in this band. These 

tunable radar systems are used in conjunction with weapons control systems for the detection and 

tracking of air and surface targets. The DOD also operates radar systems used for fleet air 

defense, missile and gunfire control, bomb scoring, battlefield weapon locations, tactical ATC, 

and range safety. The ground-based, airborne, and shipborne radar systems operating in the band 

are characterized by high-power transmitted signals and high gain antennas. The radar antennas 

rotate 360 degrees, radiating in all directions around the location of the radar. The transportable 

tactical radar systems can be authorized to operate over a large geographic area (e.g., radius of 

operation in excess of 100 kilometers) employing antennas that can be pointing in any direction. 

The combination of high transmitted power, high antenna gain, and the large operational areas 

results in significant geographic areas where there are high signal levels that can be received by 

other terrestrial users operating in the band. The airborne and shipborne radar operating in the 

band can also impact terrestrial users over significant geographic areas. This band is critical to 

military radar operations supporting national defense. 
31

7. CALCULATION OF TOTAL SPECTRUM USAGE

7.1 Introduction

This section presents the calculation of Total Spectrum Usage for the quantitative 

assessments. The quantitative assessments were performed in 5 megahertz band segments across 

the 1300-1390 MHz, 1675-1695 MHz, 2700-2900 MHz, 2900-3100 MHz, and 3100-3550 MHz 

frequency bands.47 For each 5 megahertz band segment, the frequency usage, geographic usage, 

and estimated time usage is described. Total Spectrum Usage is based on the aggregation of the 

spectrum usage contours for all the applicable agencies to represent overall usage as it relates to 

geography and population based on NTIA’s tool. The frequency usage is described in terms of 

the number of frequency assignments that fall within each 5 megahertz band segment.48 The 

geographic usage is described in terms of the percentage of the population impacted by the 

transmit and receive station spectrum usage contours and the percentage of the geographic area 

that is available (e.g., not covered by spectrum usage contours).49 The time usage is described 

using the agency provided estimates for the time a station is actually being used to perform its 

mission.50 

Experimental stations used for research and development, testing, and calibration were 

not included in the quantitative assessments since, while an important requirement for the 

agencies, they operate on a non-interference basis and will continue to do so in the future.

7.2 Total Spectrum Usage in Quantitative Assessment Frequency Bands

The agency GMF frequency assignment and spectrum certification data was used to 

generate the contours describing spectrum (frequency and bandwidth) usage, geographic usage, 

and time usage for the transmit and receive stations in the quantitative assessment bands.51 

7.2.1 1300-1390 MHz Band. Total Spectrum Usage of the 1300-1390 MHz band is

presented in Table 7-1. The corresponding spectrum usage contour plots are provided in 

Appendix A.

 

47 A 5 megahertz band segment was selected because it represents the minimum amount of contiguous spectrum 

currently under consideration for wireless broadband services. See Ten-Year Plan at 7.

48 The number of assignments, authorized by NTIA, cannot be considered independently since many systems use the 

entire band, and in some cases the number of assignments does not represent the number of equipment in use. 

Multiple pieces of radio equipment, and sometimes hundreds of devices, can operate under a single frequency 

assignment.

49 Geographic usage does not take into account US&P frequency assignments.

50 The time usage values presented in this section are based on the individual frequency assignments in each 5 

megahertz band segment and do not take into account aggregate time usage.

51 The December 2015 GMF was used for the quantitative assessment results presented in this report.
32

Table 7-1. Total Spectrum Usage in the 1300-1390 MHz Band

Band 

Segment 

(MHz)

Frequency Usage Geographic Usage Estimated Time Usage 

1300-1305 48 frequency assignments for transmit 

stations spaced across the band segment. 

1 airborne transmit station operating in 

the band segment.

Population Impacted: 63.7%

Geographic Availability: 45.1%

Figure A-1

18 stations 50-100% 

0 stations 10-50% 

30 stations 1-10% 

1 station less than 1%

1305-1310 47 frequency assignments for transmit 

stations spaced across the band segment.

Population Impacted: 75.3%

Geographic Availability: 45.8%

Figure A-2

25 stations 50-100% 

0 stations 10-50% 

22 stations 1-10% 

0 stations less than 1%

1310-1315 45 frequency assignments for transmit 

stations spaced across the band segment.

Population Impacted: 77.2%

Geographic Availability: 48.4%

Figure A-3

30 stations 50-100% 

0 stations 10-50% 

15 stations 1-10% 

0 stations less than 1%

1315-1320 61 frequency assignments for transmit 

stations spaced across the band segment.

Population Impacted: 67.6%

Geographic Availability: 44.8%

Figure A-4

31 stations 50-100% 

0 stations 10-50% 

30 stations 1-10% 

0 stations less than 1%

1320-1325 65 frequency assignments for transmit 

stations spaced across the band segment.

Population Impacted: 74.2%

Geographic Availability: 39.2%

Figure A-5

31 stations 50-100% 

0 stations 10-50% 

34 stations 1-10% 

0 stations less than 1%

1325-1330 55 frequency assignments for transmit 

stations spaced across the band segment.

Population Impacted: 78.0%

Geographic Availability: 32.0%

Figure A-6

35 stations 50-100% 

0 stations 10-50% 

20 stations 1-10% 

0 stations less than 1%

1330-1335 53 frequency assignments for transmit 

stations spaced across the band segment.

Population Impacted: 69.6%

Geographic Availability: 38.3%

Figure A-7

31 stations 50-100% 

0 stations 10-50% 

22 stations 1-10% 

0 stations less than 1%

1335-1340 50 frequency assignments for transmit 

stations spaced across the band segment.

Population Impacted: 65.5%

Geographic Availability: 48.2%

Figure A-8

24 stations 50-100% 

0 stations 10-50% 

26 stations 1-10% 

0 stations less than 1%

1340-1345 58 frequency assignments for transmit 

stations spaced across the band segment.

Population Impacted: 85.5%

Geographic Availability: 25.1%

Figure A-9

37 stations 50-100% 

0 stations 10-50% 

21 stations 1-10% 

0 stations less than 1%

1345-1350 69 frequency assignments for transmit 

stations spaced across the band segment.

1 airborne transmit station operating in 

the band segment.

Population Impacted: 85.5%

Geographic Availability: 28.4%

Figure A-10

24 stations 50-100% 

0 stations 10-50% 

45 stations 1-10% 

1 stations less than 1%

1350-1355 63 frequency assignments for transmit 

stations spaced across the band segment. 

7 airborne transmit stations operating in 

the band segment.

Population Impacted: 86.6%

Geographic Availability: 30.7%

Figure A-11

24 stations 50-100% 

0 stations 10-50% 

45 stations 1-10% 

1 station less than 1%

1355-1360 62 frequency assignments for transmit 

stations spaced across the band segment.

6 airborne transmit stations operating in 

the band segment.

Population Impacted: 51.4%

Geographic Availability: 64.6%

Figure A-12

11 stations 50-100% 

0 stations 10-50% 

56 stations 1-10% 

1 station less than 1%

1360-1365 59 frequency assignments for transmit 

stations spaced across the band segment. 

Population Impacted: 56.0%

Geographic Availability: 62.6%

Figure A-13

13 stations 50-100% 

0 stations 10-50% 

51 stations 1-10% 
33

Band 

Segment 

(MHz)

Frequency Usage Geographic Usage Estimated Time Usage 

7 airborne transmit stations operating in 

the band segment.

2 stations less than 1%

1365-1370 86 frequency assignments for transmit 

stations spaced across the band segment. 

22 airborne transmit stations operating in 

the band segment.

Population Impacted: 56.5%

Geographic Availability: 63.5%

Figure A-14

6 stations 50-100% 

0 stations 10-50% 

99 stations 1-10% 

3 stations less than 1%

1370-1375 163 frequency assignments for transmit 

stations spaced across the band segment. 

38 airborne transmit stations operating in 

the band segment.

Population Impacted: 64.5%

Geographic Availability: 59.1%

Figure A-15

3 stations 50-100% 

0 stations 10-50% 

196 stations 1-10% 

2 stations less than 1%

1375-1380 189 frequency assignments for transmit 

stations spaced across the band segment. 

27 airborne transmit stations operating in 

the band segment.

Population Impacted: 67.9%

Geographic Availability: 58.9%

Figure A-16

2 stations 50-100% 

0 stations 10-50% 

211 stations 1-10% 

3 stations less than 1%

1380-1385 198 frequency assignments for transmit 

stations spaced across the band segment. 

53 airborne transmit stations operating in 

the band segment.

Population Impacted: 65.4%

Geographic Availability: 58.8%

Figure A-17

1 stations 50-100% 

0 stations 10-50% 

248 stations 1-10% 

2 stations less than 1%

1385-1390 144 frequency assignments for transmit 

stations spaced across the band segment. 

62 airborne transmit stations operating in 

the band segment.

Population Impacted: 62.6%

Geographic Availability: 60.6%

Figure A-18

1 stations 50-100% 

0 stations 10-50% 

204 stations 1-10% 

1 station less than 1%

7.2.2 1675-1695 MHz Band. Total Spectrum Usage of the 1675-1695 MHz band is

presented in Table 7-2. Table 7-3 shows Total Spectrum Usage removing the radiosonde receive 

stations that will be migrating to the 400 MHz frequency range. The corresponding spectrum 

usage contour plots are provided in Appendix B.

Table 7-2. Total Spectrum Usage in the 1675-1695 MHz Banda

Band 

Segment 

(MHz)

Frequency Usage Geographic Usage Estimated Time Usage 

1675-1680 313 frequencies for receive stations in 

the band segment.

Population Impacted: 39.9% 

Geographic Availability: 79.0% 

Figure B-1

313 stations: 50 to 100%

1680-1685 200 frequencies for receive stations in 

the band segment.

Population Impacted: 38.5% 

Geographic Availability: 79.6% 

Figure B-2

200 stations: 50 to 100%

1685-1690 40 frequencies for receive stations in the 

band segment.

Population Impacted: 4 % 

Geographic Availability: 99.2 %

Figure B-3

40 stations: 50 to 100%

1690-1695 38 frequencies for receive stations in the 

band segment.

Population Impacted: 4.3%

Geographic Availability: 99.0% 

Figure B-4

38 stations: 50 to 100%

Note a: DOC provides data (forecasts and warnings) to non-federal end users. The impact to non-federal users is not included 

in the quantitative assessment. The impact to non-federal users will require further study.
34

Table 7-3. Total Spectrum Usage in the 1675-1695 MHz Banda

(Radiosonde Receive Stations Removed) 

Band 

Segment 

(MHz)

Frequency Usage Geographic Usage Estimated Time Usage 

1675-1680 32 frequencies for receive stations in the 

band segment.

Population Impacted: 3.2% 

Geographic Availability: 98.7% 

Figure B-5

32 stations: 50 to 100%

1680-1685 11 frequencies for receive stations in the 

band segment.

Population Impacted: 1.2% 

Geographic Availability: 99.5% 

Figure B-6

11 stations: 50 to 100%

1685-1690 39 frequencies for receive stations in the 

band segment.

Population Impacted: 4. % 

Geographic Availability: 99.2 %

Figure B-7

39 stations: 50 to 100%

1690-1695 37 frequencies for receive stations in the 

band segment.

Population Impacted: 4.3%

Geographic Availability: 99.0% 

Figure B-8

37 stations: 50 to 100%

Note a: DOC provides data (forecasts and warnings) to non-federal end users. The impact to non-federal users is not included 

in the quantitative assessment. The impact to non-federal users will require further study.

7.2.3 2700-2900 MHz Band. Total Spectrum Usage of the 2700-2900 MHz band is

presented in Table 7-4. The corresponding spectrum usage contour plots are provided in 

Appendix C.

Table 7-4. Total Spectrum Usage in the 2700-2900 MHz Band

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

2700-2705 45 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 55.0%

Geographic Availability: 73.2%

Figure C-1

35 stations 50-100%

2 stations 10-50%

8 stations 1-10%

0 stations Less than 1%

2705-2710 80 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 74.7%

Geographic Availability: 54.9%

Figure C-2

68 stations 50-100%

0 stations 10-50%

12 stations 1-10%

0 stations Less than 1%

2710-2715 82 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 71.6%

Geographic Availability: 54.9%

Figure C-3

64 stations 50-100%

0 stations 10-50%

17 stations 1-10%

1 stations Less than 1%

2715-2720 84 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 61.6%

Geographic Availability: 66.6%

Figure C-4

50 stations 50-100%

4 stations 10-50%

28 stations 1-10%

2 stations Less than 1%

2720-2725 70 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 55.6%

Geographic Availability: 66.9%

Figure C-5

51 stations 50-100%

4 stations 10-50%

13 stations 1-10%

2 stations Less than 1%

2725-2730 57 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 73.5%

Geographic Availability: 60.5%

Figure C-6

49 stations 50-100%

0 stations 10-50%

7 stations 1-10%

1 stations Less than 1%
35

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

2730-2735 53 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 72.8%

Geographic Availability: 61.6%

Figure C-7

45 stations 50-100%

0 stations 10-50%

7 stations 1-10%

1 stations Less than 1%

2735-2740 52 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 64.2%

Geographic Availability: 68.9%

Figure C-8

45 stations 50-100%

2 stations 10-50%

4 stations 1-10%

1 stations Less than 1%

2740-2745 60 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 67.9%

Geographic Availability: 64.9%

Figure C-9

53 stations 50-100%

3 stations 10-50%

3 stations 1-10%

1 stations Less than 1%

2745-2750 71 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 72.4%

Geographic Availability: 55.3%

Figure C-10

62 stations 50-100%

2 stations 10-50%

7 stations 1-10%

0 stations Less than 1%

2750-2755 50 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 63.2%

Geographic Availability: 58.7%

Figure C-11

44 stations 50-100%

0 stations 10-50%

6 stations 1-10%

0 stations Less than 1%

2755-2760 42 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 59.7%

Geographic Availability: 70.4%

Figure C-12

31 stations 50-100%

4 stations 10-50%

7 stations 1-10%

0 stations Less than 1%

2760-2765 57 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 68.6%

Geographic Availability: 62.4%

Figure C-13

38 stations 50-100%

6 stations 10-50%

13 stations 1-10%

0 stations Less than 1%

2765-2770 61 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 60.6%

Geographic Availability: 67.1%

Figure C-14

45 stations 50-100%

2 stations 10-50%

13 stations 1-10%

1 stations Less than 1%

2770-2775 55 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 55.6%

Geographic Availability: 65.7%

Figure C-15

48 stations 50-100%

0 stations 10-50%

5 stations 1-10%

2 stations Less than 1%

2775-2780 56 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 49.6%

Geographic Availability: 64.4%

Figure C-16

49 stations 50-100%

0 stations 10-50%

4 stations 1-10%

3 stations Less than 1%

2780-2785 58 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 52.8%

Geographic Availability: 69.8%

Figure C-17

47 stations 50-100%

0 stations 10-50%

10 stations 1-10%

1 stations Less than 1%

2785-2790 68 frequency assignments for transmit Population Impacted: 63.9% 47 stations 50-100%
36

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

stations spaced across the band 

segment.

Geographic Availability: 68.8%

Figure C-18

0 stations 10-50%

17 stations 1-10%

4 stations Less than 1%

2790-2795 58 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 72.8%

Geographic Availability: 71.3%

Figure C-19

41 stations 50-100%

3 stations 10-50%

10 stations 1-10%

4 stations Less than 1%

2795-2800 52 frequency assignments for transmit 

stations spaced across the band 

segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 64.9%

Geographic Availability: 68.5%

Figure C-20

34 stations 50-100%

3 stations 10-50%

15 stations 1-10%

1 stations Less than 1%

2800-2805 63 frequency assignments for transmit 

stations spaced across the band 

segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 65.4%

Geographic Availability: 67.7%

Figure C-21

39 stations 50-100%

2 stations 10-50%

22 stations 1-10%

1 stations Less than 1%

2805-2810 72 frequency assignments for transmit 

stations spaced across the band 

segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 60.1%

Geographic Availability: 67.1%

Figure C-22

46 stations 50-100%

3 stations 10-50%

21 stations 1-10%

3 stations Less than 1%

2810-2815 61 frequency assignments for transmit 

stations spaced across the band 

segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 62.2%

Geographic Availability: 66.6%

Figure C-23

52 stations 50-100%

3 stations 10-50%

4 stations 1-10%

3 stations Less than 1%

2815-2820 56 frequency assignments for transmit 

stations spaced across the band 

segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 63.8%

Geographic Availability: 68.5%

Figure C-24

50 stations 50-100%

3 stations 10-50%

3 stations 1-10%

1 stations Less than 1%

2820-2825 51 frequency assignments for transmit 

stations spaced across the band 

segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 70.9%

Geographic Availability: 66.4%

Figure C-25

44 stations 50-100%

0 stations 10-50%

5 stations 1-10%

3 stations Less than 1%

2825-2830 60 frequency assignments for transmit 

stations spaced across the band 

segment.

1 US&P transmit station operating in 

Population Impacted: 67.5%

Geographic Availability: 62.1%

Figure C-26

45 stations 50-100%

2 stations 10-50%

12 stations 1-10%

2 stations Less than 1%
37

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

the band segment.

2830-2835 62 frequency assignments for transmit 

stations spaced across the band 

segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 63.1%

Geographic Availability: 65.2%

Figure C-27

39 stations 50-100%

12 stations 10-50%

10 stations 1-10%

2 stations Less than 1%

2835-2840 56 frequency assignments for transmit 

stations spaced across the band 

segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 63.1%

Geographic Availability: 67.2%

Figure C-28

41 stations 50-100%

9 stations 10-50%

6 stations 1-10%

1 stations Less than 1%

2840-2845 61 frequency assignments for transmit 

stations spaced across the band 

segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 65.6%

Geographic Availability: 62.7%

Figure C-29

47 stations 50-100%

3 stations 10-50%

12 stations 1-10%

0 stations Less than 1%

2845-2850 53 frequency assignments for transmit 

stations spaced across the band 

segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 62.7%

Geographic Availability: 66.9%

Figure C-30

40 stations 50-100%

2 stations 10-50%

12 stations 1-10%

0 stations Less than 1%

2850-2855 41 frequency assignments for transmit 

stations spaced across the band 

segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 54.2%

Geographic Availability: 69.2%

Figure C-31

38 stations 50-100%

0 stations 10-50%

4 stations 1-10%

0 stations Less than 1%

2855-2860 55 frequency assignments for transmit 

stations spaced across the band 

segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 44.6%

Geographic Availability: 69.7%

Figure C-32

40 stations 50-100%

6 stations 10-50%

10 stations 1-10%

0 stations Less than 1%

2860-2865 65 frequency assignments for transmit 

stations spaced across the band 

segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 54.8%

Geographic Availability: 64.3%

Figure C-33

45 stations 50-100%

8 stations 10-50%

13 stations 1-10%

0 stations Less than 1%

2865-2870 74 frequency assignments for transmit 

stations spaced across the band 

segment.

1 US&P transmit station operating in 

Population Impacted: 67.9%

Geographic Availability: 55.6%

Figure C-34

58 stations 50-100%

2 stations 10-50%

13 stations 1-10%

2 stations Less than 1%
38

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

the band segment.

2870-2875 84 frequency assignments for transmit 

stations spaced across the band 

segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 69.8%

Geographic Availability: 51.8%

Figure C-35

59 stations 50-100%

4 stations 10-50%

19 stations 1-10%

3 stations Less than 1%

2875-2880 84 frequency assignments for transmit 

stations spaced across the band 

segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 66.1%

Geographic Availability: 60.4%

Figure C-36

59 stations 50-100%

4 stations 10-50%

21 stations 1-10%

1 stations Less than 1%

2880-2885 74 frequency assignments for transmit 

stations spaced across the band 

segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 64.5%

Geographic Availability: 58.0%

Figure C-37

69 stations 50-100%

0 stations 10-50%

6 stations 1-10%

0 stations Less than 1%

2885-2890 81 frequency assignments for transmit 

stations spaced across the band 

segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 70.6%

Geographic Availability: 47.9%

Figure C-38

76 stations 50-100%

0 stations 10-50%

6 stations 1-10%

0 stations Less than 1%

2890-2895 69 frequency assignments for transmit 

stations spaced across the band 

segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 67.3%

Geographic Availability: 52.6%

Figure C-39

64 stations 50-100%

0 stations 10-50%

6 stations 1-10%

0 stations Less than 1%

2895-2900 155 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating in 

the band segment.

Population Impacted: 74.5%

Geographic Availability: 47.0%

Figure C-40

133 stations 50-100%

2 stations 10-50%

22 stations 1-10%

0 stations Less than 1%

Note a: Geographic usage does not take into account US&P frequency assignments. Systems authorized under a US&P 

assignment can operate anywhere (e.g., inside or outside of the spectrum usage contours) and are not represented on the 

spectrum usage contours in the appendices. US&P assignments must be taken into account in the sharing feasibility studies.

7.2.4 2900-3100 MHz Band. Total Spectrum Usage of the 2900-3100 MHz band is

presented in Table 7-5. The corresponding spectrum usage contour plots are provided in 

Appendix D.
39

Table 7-5. Total Spectrum Usage in the 2900-3100 MHz Band

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

2900-2905 128 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 60.2%

Geographic Availability: 57.9%

Figure D-1

107 stations 50-100%

0 stations 10-50%

23 stations 1-10%

0 stations Less than 1%

2905-2910 116 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 43.9%

Geographic Availability: 71.3%

Figure D-2

97 stations 50-100%

0 stations 10-50%

21 stations 1-10%

0 stations Less than 1%

2910-2915 114 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 43.9%

Geographic Availability: 71.3%

Figure D-3

98 stations 50-100%

0 stations 10-50%

18 stations 1-10%

0 stations Less than 1%

2915-2920 115 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 43.3%

Geographic Availability: 72.8%

Figure D-4

97 stations 50-100%

0 stations 10-50%

20 stations 1-10%

0 stations Less than 1%

2920-2925 113 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 42.8%

Geographic Availability: 73.2%

Figure D-5

95 stations 50-100%

0 stations 10-50%

20 stations 1-10%

0 stations Less than 1%

2925-2930 119 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 43.8%

Geographic Availability: 72.3%

Figure D-6

96 stations 50-100%

0 stations 10-50%

24 stations 1-10%

1 stations Less than 1%

2930-2935 122 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 44.4%

Geographic Availability: 71.7%

Figure D-7

98 stations 50-100%

0 stations 10-50%

25 stations 1-10%

1 stations Less than 1%

2935-2940 122 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 44.8%

Geographic Availability: 70.9%

Figure D-8

98 stations 50-100%

0 stations 10-50%

26 stations 1-10%

0 stations Less than 1%
40

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

2940-2945 123 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 47.7%

Geographic Availability: 70.2%

Figure D-9

100 stations 50-100%

0 stations 10-50%

25 stations 1-10%

0 stations Less than 1%

2945-2950 117 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 47.1%

Geographic Availability: 71.5%

Figure D-10

99 stations 50-100%

0 stations 10-50%

20 stations 1-10%

0 stations Less than 1%

2950-2955 114 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 46.5%

Geographic Availability: 72.2%

Figure D-11

97 stations 50-100%

0 stations 10-50%

19 stations 1-10%

0 stations Less than 1%

2955-2960 116 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 46.5%

Geographic Availability: 72.1%

Figure D-12

97 stations 50-100%

0 stations 10-50%

21 stations 1-10%

0 stations Less than 1%

2960-2965 115 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 43.7%

Geographic Availability: 69.4%

Figure D-13

95 stations 50-100%

0 stations 10-50%

22 stations 1-10%

0 stations Less than 1%

2965-2970 119 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 43.7%

Geographic Availability: 69.1%

Figure D-14

95 stations 50-100%

0 stations 10-50%

26 stations 1-10%

0 stations Less than 1%

2970-2975 119 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 43.5%

Geographic Availability: 72.6%

Figure D-15

95 stations 50-100%

0 stations 10-50%

26 stations 1-10%

0 stations Less than 1%

2975-2980 120 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 44.1%

Geographic Availability: 67.5%

Figure D-16

95 stations 50-100%

0 stations 10-50%

27 stations 1-10%

0 stations Less than 1%

2980-2985 119 frequency assignments for Population Impacted: 44.1% 95 stations 50-100%
41

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Geographic Availability: 67.5%

Figure D-17

0 stations 10-50%

26 stations 1-10%

0 stations Less than 1%

2985-2990 125 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 45.7%

Geographic Availability: 65.9%

Figure D-18

102 stations 50-100%

0 stations 10-50%

25 stations 1-10%

0 stations Less than 1%

2990-2995 127 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 45.7%

Geographic Availability: 65.9%

Figure D-19

102 stations 50-100%

0 stations 10-50%

27 stations 1-10%

0 stations Less than 1%

2995-3000 130 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 46.2%

Geographic Availability: 68.0%

Figure D-20

102 stations 50-100%

1 stations 10-50%

29 stations 1-10%

0 stations Less than 1%

3000-3005 130 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 46.3%

Geographic Availability: 67.4%

Figure D-21

102 stations 50-100%

1 stations 10-50%

29 stations 1-10%

0 stations Less than 1%

3005-3010 122 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating 

in the band segment.

Population Impacted: 45.0%

Geographic Availability: 67.3%

Figure D-22

97 stations 50-100%

0 stations 10-50%

26 stations 1-10%

0 stations Less than 1%

3010-3015 120 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating 

in the band segment.

Population Impacted: 45.0%

Geographic Availability: 67.3%

Figure D-23

97 stations 50-100%

0 stations 10-50%

24 stations 1-10%

0 stations Less than 1%

3015-3020 120 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 46.2%

Geographic Availability: 70.3%

Figure D-24

97 stations 50-100%

0 stations 10-50%

25 stations 1-10%

0 stations Less than 1%

3020-3025 130 frequency assignments for 

transmit stations spaced across the 

Population Impacted: 47.5%

Geographic Availability: 69.9%

98 stations 50-100%

0 stations 10-50%
42

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

band segment.

2 US&P transmit stations operating 

in the band segment.

Figure D-25 34 stations 1-10%

0 stations Less than 1%

3025-3030 132 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 48.1%

Geographic Availability: 68.9%

Figure D-26

98 stations 50-100%

0 stations 10-50%

36 stations 1-10%

0 stations Less than 1%

3030-3035 133 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 48.1%

Geographic Availability: 68.9%

Figure D-27

98 stations 50-100%

0 stations 10-50%

37 stations 1-10%

0 stations Less than 1%

3035-3040 137 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 57.4%

Geographic Availability: 67.2%

Figure D-28

97 stations 50-100%

0 stations 10-50%

37 stations 1-10%

5 stations Less than 1%

3040-3045 136 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 57.4%

Geographic Availability: 67.2%

Figure D-29

97 stations 50-100%

0 stations 10-50%

36 stations 1-10%

5 stations Less than 1%

3045-3050 141 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 59.7%

Geographic Availability: 66.2%

Figure D-30

98 stations 50-100%

0 stations 10-50%

37 stations 1-10%

8 stations Less than 1%

3050-3055 142 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 59.7%

Geographic Availability: 66.2%

Figure D-31

98 stations 50-100%

0 stations 10-50%

38 stations 1-10%

8 stations Less than 1%

3055-3060 138 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 59.7%

Geographic Availability: 66.1%

Figure D-32

97 stations 50-100%

0 stations 10-50%

38 stations 1-10%

5 stations Less than 1%

3060-3065 135 frequency assignments for 

transmit stations spaced across the 

band segment.

Population Impacted: 57.4%

Geographic Availability: 67.2%

97 stations 50-100%

0 stations 10-50%

35 stations 1-10%
43

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

2 US&P transmit stations operating 

in the band segment.

Figure D-33 5 stations Less than 1%

3065-3070 128 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 47.5%

Geographic Availability: 69.9%

Figure D-34

97 stations 50-100%

0 stations 10-50%

33 stations 1-10%

0 stations Less than 1%

3070-3075 129 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 47.5%

Geographic Availability: 69.9%

Figure D-35

97 stations 50-100%

0 stations 10-50%

34 stations 1-10%

0 stations Less than 1%

3075-3080 125 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 46.9%

Geographic Availability: 70.8%

Figure D-36

96 stations 50-100%

0 stations 10-50%

31 stations 1-10%

0 stations Less than 1%

3080-3085 115 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 45.1%

Geographic Availability: 72.3%

Figure D-37

95 stations 50-100%

0 stations 10-50%

22 stations 1-10%

0 stations Less than 1%

3085-3090 112 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating 

in the band segment.

Population Impacted: 42.8%

Geographic Availability: 73.2%

Figure D-38

95 stations 50-100%

0 stations 10-50%

18 stations 1-10%

0 stations Less than 1%

3090-3095 120 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating 

in the band segment.

Population Impacted: 44.9%

Geographic Availability: 72.3%

Figure D-39

95 stations 50-100%

0 stations 10-50%

26 stations 1-10%

0 stations Less than 1%

3095-3100 151 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 64.5%

Geographic Availability: 45.6%

Figure D-40

94 stations 50-100%

0 stations 10-50%

57 stations 1-10%

2 stations Less than 1%

Note a: Geographic usage does not take into account US&P frequency assignments. Systems authorized under a US&P 

assignment can operate anywhere (e.g., inside or outside of the spectrum usage contours) and are not represented on the 

spectrum usage contours in the appendices. US&P assignments must be taken into account in the sharing feasibility studies.
44

7.2.5 3100-3550 MHz Band. Total Spectrum Usage of the 3100-3550 MHz band is

presented in Table 7-6. The corresponding spectrum usage contour plots are provided in 

Appendix E.

Table 7-6. Total Spectrum Usage in the 3100-3550 MHz Band

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

3100-3105 150 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 64.5%

Geographic Availability: 45.6%

Figure E-1

94 stations 50-100%

0 stations 10-50%

56 stations 1-10%

2 stations Less than 1%

3105-3110 43 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 58.9%

Geographic Availability: 57.6%

Figure E-2

0 stations 50-100%

0 stations 10-50%

42 stations 1-10%

2 stations Less than 1%

3110-3115 36 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 58.9%

Geographic Availability: 57.6%

Figure E-3

0 stations 50-100%

0 stations 10-50%

35 stations 1-10%

2 stations Less than 1%

3115-3120 35 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 58.9%

Geographic Availability: 57.6%

Figure E-4

0 stations 50-100%

0 stations 10-50%

34 stations 1-10%

2 stations Less than 1%

3120-3125 34 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 58.9%

Geographic Availability: 57.7%

Figure E-5

0 stations 50-100%

0 stations 10-50%

33 stations 1-10%

2 stations Less than 1%

3125-3130 35 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 58.9%

Geographic Availability: 57.7%

Figure E-6

0 stations 50-100%

0 stations 10-50%

34 stations 1-10%

2 stations Less than 1%

3130-3135 35 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 58.9%

Geographic Availability: 57.6%

Figure E-7

0 stations 50-100%

0 stations 10-50%

34 stations 1-10%

2 stations Less than 1%
45

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

3135-3140 35 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 58.9%

Geographic Availability: 57.6%

Figure E-8

0 stations 50-100%

0 stations 10-50%

34 stations 1-10%

2 stations Less than 1%

3140-3145 65 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 78.0%

Geographic Availability: 35.7%

Figure E-9

0 stations 50-100%

0 stations 10-50%

64 stations 1-10%

2 stations Less than 1%

3145-3150 67 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 78.0%

Geographic Availability: 35.7%

Figure E-10

0 stations 50-100%

0 stations 10-50%

66 stations 1-10%

2 stations Less than 1%

3150-3155 37 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 58.9%

Geographic Availability: 57.6%

Figure E-11

0 stations 50-100%

0 stations 10-50%

36 stations 1-10%

2 stations Less than 1%

3155-3160 35 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 58.9%

Geographic Availability: 57.6%

Figure E-12

0 stations 50-100%

0 stations 10-50%

34 stations 1-10%

2 stations Less than 1%

3160-3165 35 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 58.9%

Geographic Availability: 57.6%

Figure E-13

0 stations 50-100%

1 stations 10-50%

33 stations 1-10%

2 stations Less than 1%

3165-3170 34 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 58.9%

Geographic Availability: 57.6%

Figure E-14

0 stations 50-100%

0 stations 10-50%

33 stations 1-10%

2 stations Less than 1%

3170-3175 34 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 58.9%

Geographic Availability: 57.6%

Figure E-15

0 stations 50-100%

0 stations 10-50%

33 stations 1-10%

2 stations Less than 1%

3175-3180 37 frequency assignments for Population Impacted: 60.2% 0 stations 50-100%
46

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Geographic Availability: 56.7%

Figure E-16

0 stations 10-50%

33 stations 1-10%

5 stations Less than 1%

3180-3185 38 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 60.2%

Geographic Availability: 56.7%

Figure E-17

0 stations 50-100%

1 stations 10-50%

33 stations 1-10%

5 stations Less than 1%

3185-3190 34 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 58.9%

Geographic Availability: 57.6%

Figure E-18

0 stations 50-100%

0 stations 10-50%

33 stations 1-10%

2 stations Less than 1%

3190-3195 38 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 59.6%

Geographic Availability: 57.3%

Figure E-19

0 stations 50-100%

0 stations 10-50%

38 stations 1-10%

4 stations Less than 1%

3195-3200 38 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 59.6%

Geographic Availability: 57.3%

Figure E-20

0 stations 50-100%

0 stations 10-50%

38 stations 1-10%

4 stations Less than 1%

3200-3205 36 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 59.5%

Geographic Availability: 57.5%

Figure E-21

0 stations 50-100%

0 stations 10-50%

38 stations 1-10%

2 stations Less than 1%

3205-3210 37 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

1 US&P transmit station operating in 

Population Impacted: 59.5%

Geographic Availability: 57.5%

Figure E-22

0 stations 50-100%

1 stations 10-50%

38 stations 1-10%

2 stations Less than 1%
47

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

the band segment.

3210-3215 35 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 59.0%

Geographic Availability: 57.6%

Figure E-23

0 stations 50-100%

0 stations 10-50%

37 stations 1-10%

2 stations Less than 1%

3215-3220 63 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 78.3%

Geographic Availability: 35.7%

Figure E-24

0 stations 50-100%

0 stations 10-50%

65 stations 1-10%

2 stations Less than 1%

3220-3225 64 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 78.3%

Geographic Availability: 35.7%

Figure E-25

0 stations 50-100%

0 stations 10-50%

65 stations 1-10%

3 stations Less than 1%

3225-3230 37 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 59.9%

Geographic Availability: 56.5%

Figure E-26

0 stations 50-100%

1 stations 10-50%

37 stations 1-10%

3 stations Less than 1%

3230-3235 38 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 59.9%

Geographic Availability: 56.5%

Figure E-27

0 stations 50-100%

1 stations 10-50%

38 stations 1-10%

3 stations Less than 1%

3235-3240 37 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

Population Impacted: 59.9%

Geographic Availability: 56.5%

Figure E-28

0 stations 50-100%

0 stations 10-50%

38 stations 1-10%

3 stations Less than 1%
48

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

1 US&P transmit station operating in 

the band segment.

3240-3245 36 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 59.0%

Geographic Availability: 57.6%

Figure E-29

0 stations 50-100%

0 stations 10-50%

38 stations 1-10%

2 stations Less than 1%

3245-3250 37 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 59.0%

Geographic Availability: 57.6%

Figure E-30

0 stations 50-100%

0 stations 10-50%

39 stations 1-10%

2 stations Less than 1%

3250-3255 41 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 69.6%

Geographic Availability: 46.8%

Figure E-31

0 stations 50-100%

0 stations 10-50%

42 stations 1-10%

3 stations Less than 1%

3255-3260 40 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 69.6%

Geographic Availability: 46.8%

Figure E-32

0 stations 50-100%

0 stations 10-50%

41 stations 1-10%

3 stations Less than 1%

3260-3265 34 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 59.0%

Geographic Availability: 57.6%

Figure E-33

0 stations 50-100%

0 stations 10-50%

36 stations 1-10%

2 stations Less than 1%

3265-3270 34 frequency assignments for 

transmit stations spaced across the 

band segment.

Population Impacted: 59.0%

Geographic Availability: 57.6%

Figure E-34

0 stations 50-100%

0 stations 10-50%

36 stations 1-10%
49

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

3 airborne transmit stations operating 

in the band segment.

1 US&P transmit station operating in 

the band segment.

2 stations Less than 1%

3270-3275 35 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 59.8%

Geographic Availability: 57.0%

Figure E-35

0 stations 50-100%

0 stations 10-50%

36 stations 1-10%

3 stations Less than 1%

3275-3280 36 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 60.2%

Geographic Availability: 56.7%

Figure E-36

0 stations 50-100%

0 stations 10-50%

36 stations 1-10%

4 stations Less than 1%

3280-3285 36 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 59.5%

Geographic Availability: 57.3%

Figure E-37

0 stations 50-100%

0 stations 10-50%

36 stations 1-10%

4 stations Less than 1%

3285-3290 35 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 59.5%

Geographic Availability: 57.3%

Figure E-38

0 stations 50-100%

0 stations 10-50%

36 stations 1-10%

3 stations Less than 1%

3290-3295 35 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 59.0%

Geographic Availability: 57.2%

Figure E-39

0 stations 50-100%

0 stations 10-50%

37 stations 1-10%

2 stations Less than 1%

3295-3300 36 frequency assignments for 

transmit stations spaced across the 

Population Impacted: 59.0%

Geographic Availability: 57.2%

0 stations 50-100%

0 stations 10-50%
50

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

band segment.

3 airborne transmit stations operating 

in the band segment.

1 US&P transmit station operating in 

the band segment.

Figure E-40 38 stations 1-10%

2 stations Less than 1%

3300-3305 34 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 58.9%

Geographic Availability: 57.6%

Figure E-41

0 stations 50-100%

0 stations 10-50%

33 stations 1-10%

2 stations Less than 1%

3305-3310 59 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 77.5%

Geographic Availability: 35.9%

Figure E-42

0 stations 50-100%

0 stations 10-50%

58 stations 1-10%

2 stations Less than 1%

3310-3315 59 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 77.5%

Geographic Availability: 35.9%

Figure E-43

0 stations 50-100%

0 stations 10-50%

58 stations 1-10%

2 stations Less than 1%

3315-3320 34 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 58.9%

Geographic Availability: 57.7%

Figure E-44

0 stations 50-100%

0 stations 10-50%

33 stations 1-10%

2 stations Less than 1%

3320-3325 34 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 58.9%

Geographic Availability: 57.6%

Figure E-45

0 stations 50-100%

0 stations 10-50%

33 stations 1-10%

2 stations Less than 1%

3325-3330 36 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 58.9%

Geographic Availability: 57.5%

Figure E-46

0 stations 50-100%

0 stations 10-50%

35 stations 1-10%

2 stations Less than 1%

3330-3335 40 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 68.8%

Geographic Availability: 47.4%

Figure E-47

0 stations 50-100%

0 stations 10-50%

39 stations 1-10%

2 stations Less than 1%
51

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

3335-3340 37 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 68.8%

Geographic Availability: 47.6%

Figure E-48

0 stations 50-100%

0 stations 10-50%

36 stations 1-10%

2 stations Less than 1%

3340-3345 35 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

3 US&P transmit stations operating 

in the band segment.

Population Impacted: 66.5%

Geographic Availability: 51.1%

Figure E-49

0 stations 50-100%

0 stations 10-50%

39 stations 1-10%

2 stations Less than 1%

3345-3350 34 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

3 US&P transmit stations operating 

in the band segment.

Population Impacted: 60.2%

Geographic Availability: 55.6%

Figure E-50

0 stations 50-100%

0 stations 10-50%

38 stations 1-10%

2 stations Less than 1%

3350-3355 33 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

3 US&P transmit stations operating 

in the band segment.

Population Impacted: 60.2%

Geographic Availability: 55.7%

Figure E-51

0 stations 50-100%

0 stations 10-50%

37 stations 1-10%

2 stations Less than 1%

3355-3360 38 frequency assignments for 

transmit stations spaced across the 

band segment.

3 airborne transmit stations operating 

in the band segment.

3 US&P transmit stations operating 

in the band segment.

Population Impacted: 69.5%

Geographic Availability: 46.6%

Figure E-52

0 stations 50-100%

0 stations 10-50%

42 stations 1-10%

2 stations Less than 1%

3360-3365 38 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 68.7%

Geographic Availability: 47.8%

Figure E-53

0 stations 50-100%

0 stations 10-50%

38 stations 1-10%

2 stations Less than 1%

3365-3370 37 frequency assignments for 

transmit stations spaced across the 

band segment.

Population Impacted: 67.9%

Geographic Availability: 49.5%

Figure E-54

0 stations 50-100%

0 stations 10-50%

37 stations 1-10%
52

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

2 US&P transmit stations operating 

in the band segment.

2 stations Less than 1%

3370-3375 35 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 61.4%

Geographic Availability: 54.5%

Figure E-55

0 stations 50-100%

0 stations 10-50%

35 stations 1-10%

2 stations Less than 1%

3375-3380 53 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 75.5%

Geographic Availability: 38.3%

Figure E-56

0 stations 50-100%

0 stations 10-50%

53 stations 1-10%

2 stations Less than 1%

3380-3385 53 frequency assignments for 

transmit stations spaced across the 

band segment.

2 airborne transmit stations operating 

in the band segment.

4 US&P transmit stations operating 

in the band segment.

Population Impacted: 75.5%

Geographic Availability: 38.3%

Figure E-57

0 stations 50-100%

0 stations 10-50%

57 stations 1-10%

2 stations Less than 1%

3385-3390 34 frequency assignments for 

transmit stations spaced across the 

band segment.

2 airborne transmit stations operating 

in the band segment.

4 US&P transmit stations operating 

in the band segment.

Population Impacted: 58.9%

Geographic Availability: 57.0%

Figure E-58

0 stations 50-100%

1 stations 10-50%

37 stations 1-10%

2 stations Less than 1%

3390-3395 33 frequency assignments for 

transmit stations spaced across the 

band segment.

2 airborne transmit stations operating 

in the band segment.

4 US&P transmit stations operating 

in the band segment.

Population Impacted: 59.0%

Geographic Availability: 57.0%

Figure E-59

0 stations 50-100%

0 stations 10-50%

37 stations 1-10%

2 stations Less than 1%

3395-3400 24 frequency assignments for 

transmit stations spaced across the 

band segment.

2 airborne transmit stations operating 

in the band segment.

4 US&P transmit stations operating 

in the band segment.

Population Impacted: 45.4%

Geographic Availability: 74.9%

Figure E-60

0 stations 50-100%

0 stations 10-50%

28 stations 1-10%

2 stations Less than 1%
53

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

3400-3405 24 frequency assignments for 

transmit stations spaced across the 

band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 42.8%

Geographic Availability: 76.0%

Figure E-61

0 stations 50-100%

0 stations 10-50%

24 stations 1-10%

2 stations Less than 1%

3405-3410 12 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 35.5%

Geographic Availability: 81.1%

Figure E-62

0 stations 50-100%

0 stations 10-50%

11 stations 1-10%

2 stations Less than 1%

3410-3415 19 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 42.3%

Geographic Availability: 76.8%

Figure E-63

0 stations 50-100%

0 stations 10-50%

18 stations 1-10%

2 stations Less than 1%

3415-3420 18 frequency assignments for 

transmit stations spaced across the 

band segment.

1 US&P transmit station operating in 

the band segment.

Population Impacted: 42.3%

Geographic Availability: 76.8%

Figure E-64

0 stations 50-100%

0 stations 10-50%

17 stations 1-10%

2 stations Less than 1%

3420-3425 12 frequency assignments for 

transmit stations spaced across the 

band segment.

Population Impacted: 19.0%

Geographic Availability: 84.9%

Figure E-65

0 stations 50-100%

0 stations 10-50%

10 stations 1-10%

2 stations Less than 1%

3425-3430 38 frequency assignments for 

transmit stations spaced across the 

band segment.

Population Impacted: 76.3%

Geographic Availability: 39.3%

Figure E-66

0 stations 50-100%

0 stations 10-50%

36 stations 1-10%

2 stations Less than 1%

3430-3435 37 frequency assignments for 

transmit stations spaced across the 

band segment.

Population Impacted: 76.3%

Geographic Availability: 39.3%

Figure E-67

0 stations 50-100%

0 stations 10-50%

35 stations 1-10%

2 stations Less than 1%

3435-3440 11 frequency assignments for 

transmit stations spaced across the 

band segment.

Population Impacted: 19.0%

Geographic Availability: 85.0%

Figure E-68

0 stations 50-100%

0 stations 10-50%

9 stations 1-10%

2 stations Less than 1%

3440-3445 12 frequency assignments for 

transmit stations spaced across the 

band segment.

Population Impacted: 35.6%

Geographic Availability: 81.1%

Figure E-69

0 stations 50-100%

0 stations 10-50%

10 stations 1-10%

2 stations Less than 1%

3445-3450 17 frequency assignments for 

transmit stations spaced across the 

band segment.

Population Impacted: 43.1%

Geographic Availability: 76.6%

Figure E-70

0 stations 50-100%

0 stations 10-50%

15 stations 1-10%
54

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

2 stations Less than 1%

3450-3455 18 frequency assignments for 

transmit stations spaced across the 

band segment.

Population Impacted: 43.1%

Geographic Availability: 76.6%

Figure E-71

0 stations 50-100%

0 stations 10-50%

16 stations 1-10%

2 stations Less than 1%

3455-3460 13 frequency assignments for 

transmit stations spaced across the 

band segment.

Population Impacted: 37.2%

Geographic Availability: 80.1%

Figure E-72

0 stations 50-100%

0 stations 10-50%

11 stations 1-10%

2 stations Less than 1%

3460-3465 11 frequency assignments for 

transmit stations spaced across the 

band segment.

2 airborne transmit stations operating 

in the band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 21.6%

Geographic Availability: 83.9%

Figure E-73

0 stations 50-100%

0 stations 10-50%

13 stations 1-10%

2 stations Less than 1%

3465-3470 15 frequency assignments for 

transmit stations spaced across the 

band segment.

2 airborne transmit stations operating 

in the band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 44.9%

Geographic Availability: 75.8%

Figure E-74

0 stations 50-100%

0 stations 10-50%

17 stations 1-10%

2 stations Less than 1%

3470-3475 15 frequency assignments for 

transmit stations spaced across the 

band segment.

2 airborne transmit stations operating 

in the band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 44.9%

Geographic Availability: 75.8%

Figure E-75

0 stations 50-100%

0 stations 10-50%

17 stations 1-10%

2 stations Less than 1%

3475-3480 11 frequency assignments for 

transmit stations spaced across the

band segment.

2 airborne transmit stations operating 

in the band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 21.6%

Geographic Availability: 83.9%

Figure E-76

0 stations 50-100%

0 stations 10-50%

13 stations 1-10%

2 stations Less than 1%

3480-3485 11 frequency assignments for 

transmit stations spaced across the 

band segment.

Population Impacted: 19.0%

Geographic Availability: 85.0%

Figure E-77

0 stations 50-100%

0 stations 10-50%

9 stations 1-10%

2 stations Less than 1%
55

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

3485-3490 37 frequency assignments for 

transmit stations spaced across the 

band segment.

Population Impacted: 75.4%

Geographic Availability: 39.2%

Figure E-78

0 stations 50-100%

0 stations 10-50%

35 stations 1-10%

2 stations Less than 1%

3490-3495 37 frequency assignments for 

transmit stations spaced across the 

band segment.

Population Impacted: 75.4%

Geographic Availability: 39.2%

Figure E-79

0 stations 50-100%

0 stations 10-50%

35 stations 1-10%

2 stations Less than 1%

3495-3500 11 frequency assignments for 

transmit stations spaced across the 

band segment.

Population Impacted: 19.0%

Geographic Availability: 85.0%

Figure E-80

0 stations 50-100%

0 stations 10-50%

9 stations 1-10%

2 stations Less than 1%

3500-3505 11 frequency assignments for 

transmit stations spaced across the 

band segment.

2 airborne transmit stations operating 

in the band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 21.6%

Geographic Availability: 83.9%

Figure E-81

1 stations 50-100%

0 stations 10-50%

12 stations 1-10%

2 stations Less than 1%

3505-3510 0 frequency assignments for transmit 

stations spaced across the band 

segment.

2 airborne transmit stations operating 

in the band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 9.7%

Geographic Availability: 97.5%

Figure E-82

1 stations 50-100%

0 stations 10-50%

3 stations 1-10%

0 stations Less than 1%

3510-3515 0 frequency assignments for transmit 

stations spaced across the band 

segment.

2 airborne transmit stations operating 

in the band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 9.7%

Geographic Availability: 97.5%

Figure E-83

1 stations 50-100%

0 stations 10-50%

3 stations 1-10%

0 stations Less than 1%

3515-3520 0 frequency assignments for transmit 

stations spaced across the band 

segment.

2 airborne transmit stations operating 

in the band segment.

2 US&P transmit stations operating 

in the band segment.

Population Impacted: 9.7%

Geographic Availability: 97.5%

Figure E-84

1 stations 50-100%

0 stations 10-50%

3 stations 1-10%

0 stations Less than 1%

3520-3525 0 frequency assignments for transmit 

stations spaced across the band 

Population Impacted: 0.0000%

Geographic Availability: 100.0000%

0 stations 50-100%

0 stations 10-50%

0 stations 1-10%
56

Band 

Segment 

(MHz)

Frequency Usage Geographic Usagea Estimated Time Usage 

segment. Figure E-85 0 stations Less than 1%

3525-3530 0 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 0.0000%

Geographic Availability: 100.0000%

Figure E-86

0 stations 50-100%

0 stations 10-50%

0 stations 1-10%

0 stations Less than 1%

3530-3535 0 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 0.0000%

Geographic Availability: 100.0000%

Figure E-87

0 stations 50-100%

0 stations 10-50%

0 stations 1-10%

0 stations Less than 1%

3535-3540 0 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 0.0000%

Geographic Availability: 100.0000%

Figure E-88

0 stations 50-100%

0 stations 10-50%

0 stations 1-10%

0 stations Less than 1%

3540-3545 0 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 0.0000%

Geographic Availability: 100.0000%

Figure E-89

0 stations 50-100%

0 stations 10-50%

0 stations 1-10%

0 stations Less than 1%

3545-3550 0 frequency assignments for transmit 

stations spaced across the band 

segment.

Population Impacted: 0.0000%

Geographic Availability: 100.0000%

Figure E-90

0 stations 50-100%

0 stations 10-50%

0 stations 1-10%

0 stations Less than 1%

Note a: Geographic usage does not take into account US&P frequency assignments. Systems authorized under a US&P 

assignment can operate anywhere (e.g., inside or outside of the spectrum usage contours) and are not represented on the 

spectrum usage contours in the appendices. US&P assignments must be taken into account in the sharing feasibility studies.
57

8. RESULTS OF QUANTITATIVE ASSESSMENTS

8.1 Introduction

This section presents the results of the quantitative assessments for the: 1300-1390 MHz, 

1675-1695 MHz, 2700-2900 MHz, 2900-3100 MHz, and 3100-3550 MHz bands. To the extent 

the applicable agencies provided responses on projections for future spectrum usage, potential 

access to non-federal spectrum, and risks to mission requirements, this information was used in 

conjunction with Total Spectrum Usage calculations. Based on the quantitative assessments, 

potential sharing opportunities are identified.

In order to identify potential frequency, geographic, and time sharing opportunities in a 

band, NTIA developed criteria and applied it to the assignment data used in the quantitative 

assessment (see Table 1-1). The quantitative assessment data is one input for consideration of 

potential sharing opportunities, but other factors would have to be considered in any detailed 

feasibility assessment before any conclusions could be reached. Pursuant to the President’s 2013 

memorandum, in identifying spectrum bands with the greatest potential to be shared, NTIA and 

the Spectrum Policy Team are to consider the number and nature of federal and non-federal 

systems in the band, the technical suitability of the band for shared use, international 

implications, any potential for relocating federal systems to comparable spectrum or otherwise 

enabling comparable capabilities, and other factors NTIA and the Spectrum Policy Team deem 

relevant based on consultation with agencies and other stakeholders. These include, for example,

the need to take into account mission requirements that can impact federal and non-federal users.

In general, frequency sharing is possible when there is no frequency overlap. For 

frequency sharing opportunities, the criterion is applied where no assignments fall within a 5 

megahertz segment. Geographic sharing is possible when the impact to population is low and 

the available geographic area is high. In considering geographic sharing opportunities based on 

the quantitative assessment, the criterion is based on the percentage of population impacted being 

less than 60 percent and the percentage of geographic area available exceeding 50 percent.52 

Time sharing may be possible when systems are using the spectrum for a low percentage of time. 

For time sharing opportunities, the criterion is applied where the estimated time usage within 70 

percent of the 5 megahertz segments in a frequency band is less than 10 percent. 

8.2 1300-1390 MHz Band

8.2.1 Total Spectrum Usage. Total Spectrum Usage in Table 7-1 for the 1300-1350 

MHz portion of the band shows the number of frequency assignments across each of the 5 

megahertz band segments range from 45 to 68. Based on the aggregation of the frequency usage 

data, and the criteria NTIA developed, the heavy and diverse use of the band will limit the 

 

52 US&P assignments were not included in the contours used to assess geographic sharing opportunities. Systems 

authorized under a US&P assignment have the potential to operate anywhere in the United States but can only be at 

a single location at a given period of time, which are undetermined. The feasibility studies assessing potential 

sharing opportunities will have to take US&P operations into account.
58

opportunities for frequency sharing in the 1300-1350 MHz frequency range. The aggregate 

geographic usage component of Total Spectrum Usage shows that large percentages of the 

population can be impacted, ranging from 63.7 percent to 85.5 percent across the 5 megahertz 

band segments. The percentage of geographic area available in the 5 megahertz band segments 

ranged from 24.6 percent to 47.1 percent. Geographic sharing opportunities in the 1300-1350 

MHz frequency range will be limited according to the quantitative assessment. The long-range 

surveillance radars operated by the FAA, with DOD and DHS, support ATC safety-of-life 

functions in the NAS and operate essentially 100 percent of the time, eliminating any potential 

opportunities for time sharing in the 1300-1350 MHz frequency range as long as these systems 

remain in the band. Other tactical systems that also operate in the band could have an impact on 

potential sharing opportunities.

Total Spectrum Usage in Table 7-1 for the 1350-1390 MHz portion of the band shows the 

number of frequency assignments in the 5 megahertz band segments range from 69 to 251. 

There are also a large number of frequency assignments for airborne transmit stations in the 

1350-1390 MHz sub-band. Based on the aggregation of the frequency usage data, and the 

criteria NTIA developed, there are no opportunities for frequency sharing in the 1350-1390 MHz 

frequency range exist. The aggregate geographic usage component of Total Spectrum Usage 

shows that large percentages of the population can be impacted, ranging from 51.3 percent to 

86.2 percent across the 5 megahertz band segments. The percentage of geographic area available 

ranged from 24.6 percent to 64.3 percent in the 5 megahertz band segments. The geographic 

sharing opportunities in the 1350-1390 MHz frequency range are limited according to the 

quantitative assessment. Many of the transmit stations show a time usage ranging from 1 percent 

to 10 percent. With the exception of the small number of FAA long-range surveillance radar 

systems, there is an opportunity for time sharing with the terrestrial and airborne systems 

operating in the 1365-1390 MHz frequency range. 

8.2.2 Projections for Future Spectrum Usage. As discussed in Sections 1.4.2 and 

1.4.4, an interagency activity is developing plans to analyze the feasibility of moving the 

aeronautical long-range radar capabilities from existing spectrum allocations, including the 

1300-1350 MHz band, into the 2700-3100 MHz band, as part of the SENSR capability. Such a 

potential relocation from the 1300-1350 MHz band is contingent on the development, funding 

and outcome of the feasibility study. 

The National Aeronautics and Space Administration (NASA) operates a limited number 

of terrestrial radar systems in the band and can vacate the frequency band as long as suitable 

frequency assignments can be accommodated within the 1215-1300 MHz frequency range. 

DHS plans to continue operating its terrestrial and tethered aerostat radar systems for the 

foreseeable future. DHS does plan on deploying new systems in the 1350-1390 MHz portion of 

the band. At this time, DHS is not planning to make any changes to the mission requirements 

that the systems operating in 1300-1390 MHz band support. DHS anticipates that they will 

require continued access to the 1350-1390 MHz band at a limited number of locations to support 

its mission requirements for the foreseeable future.
59

The USCG is experimenting with unmanned aircraft system (UAS) in the 1300-1390 

MHz band. However, final development may be in a different frequency band. The 

geographical area for UAS operations will most likely be United States and Possessions (US&P). 

UAS development may take several years to become fully operational. The USCG plans on 

submitting a request for spectrum support to NTIA once the technology has been developed. 

DHS and other federal agencies that are responsible for rescue and security operations may

benefit from the USCG UAS. The USCG spectrum usage for UAS may increase in the 1300-

1390 MHz band; however, the actual percentage increase in the spectrum usage will depend on 

the final system development. 

The Army reported that at the present time it does not plan to design new systems in the 

1300-1390 MHz band. Modifications to the existing systems may not require additional 

spectrum within the 1300-1390 MHz band. Based on the current information that is available, 

the Army anticipates that the present spectrum requirements in the 1300-1390 MHz band are 

expected to remain unchanged.

The Navy and Marine Corps reported that they plan on continuing to operate systems in 

the 1350-1390 MHz band. It is anticipated that they will need additional frequencies in the band 

to support future operations. They also have plans to expand the geographic areas where they 

operate. The Navy and Marine Corps also expect that the time of usage for their systems will 

increase in the future. 

The Air Force reported that they do not foresee any changes to the geographic use, 

spectrum requirements, or time of usage for its systems operating in this band. For the 

foreseeable future, the Air Force also does not anticipate any relocation of systems from the band 

or modifications that would impact the geographic usage, frequency/bandwidth requirements, or 

time usage for its systems operating in the 1300-1390 MHz band.

8.2.3 Federal Access to Non-Federal Spectrum. The federal agencies with operations 

in this band did not identify non-federal spectrum that could be used to help fulfill their missions. 

8.2.4 Risks to Agency Mission Requirements. The long-range radars in the 1300-

1350 MHz band support safety-of-life applications, and as such, any risks of harmful 

interference are not acceptable. At this time, the FAA is exploring the feasibility of making 

changes to the mission requirements for the long-range radars operating in the 1300-1350 MHz 

portion of the band. It is too early in the SENSR program to determine how it may impact 

systems in the future. Ultimately other measures would be necessary in order to enable sharing 

in the band, including consideration of potential relocation of major widely deployed systems to 

other bands if feasible. A detailed study of the feasibility of relocating systems out of the band 

would have numerous factors to consider beyond the results of the quantitative assessment. 

8.3 1675-1695 MHz Band

8.3.1 Total Spectrum Usage. Total Spectrum Usage in Table 7-2 shows a significant 

number of meteorological-satellite and radiosonde receive stations in the 1675-1685 MHz 

portion of the band across each of the 5 megahertz band segments and a much smaller number in 
60

the 1685-1695 MHz portion of the band. In the 1675-1680 MHz portion of the band, there are 

313 receive stations and in the 1680-1685 MHz portion of the band there are 200 receive 

stations. In the 1685-1690 MHz portion of the band, there are 40 receive stations and in the 

1690-1695 MHz portion of the band there are 38 receive stations. Based on the quantitative 

assessment aggregation of the frequency usage data, no opportunities for frequency sharing in 

the 1675-1695 MHz band exist. The aggregate geographic usage component of Total Spectrum 

Usage shows that the percentage of population impacted ranged from 3.99 percent to 39.8

percent.

53

 The percentage of geographic area available is high across the 1675-1695 MHz band

ranging from 79 percent to 99.2 percent. There are geographic sharing opportunities with federal 

receive stations in the 1675-1695 MHz band, contingent upon the successful completion of a 

feasibility study. 

The DOC is in the process of relocating radiosonde systems in the 1675-1695 MHz band

to the 400.15-406 MHz band. Total Spectrum Usage in Table 7-3 and the spectrum usage 

contours plots in Appendix B as shown do not include the radiosonde receive stations. As shown 

in Table 7-3, the migration of the radiosondes to the 400.15-406 MHz band will significantly 

improve the opportunities for geographic sharing. However, a sharing feasibility study needs to 

be performed to assess the potential impact to GOES receive stations that will remain in the 

1675-1695 MHz band.

The frequency, geographic, and time usage for the 1675-1695 MHz band shown in Table 

7-2 and Table 7-3 does not reflect non-federal use of the band.

8.3.2 Projections for Future Spectrum Usage. The DOC provided information 

describing projected frequency and bandwidth plans for the GOES-R and GOES-NEXT 

meteorological-satellites. The overall bandwidth requirements for GOES-R are the same as the 

legacy GOES satellites. GOES-NEXT will increase the total bandwidth requirements in the 

1675-1695 MHz band.

The Army reported that at the present time it does not plan to design new systems for the 

1675-1695 MHz band. Modifications to the existing systems will not require additional 

spectrum within the 1675-1695 MHz band. Based on the current information that is available, 

the Army anticipates that its present spectrum requirements in the 1675-1695 MHz band are 

expected to remain unchanged.

The Navy and Marine Corps reported that at the present time they do not plan to design 

new systems for the 1675-1695 MHz band. Modifications to the existing systems will not 

require additional spectrum within the 1675-1695 MHz band. Based on the currently available

information, the Navy anticipates that its present spectrum requirements in the 1675-1695 MHz 

band are expected to remain unchanged.

The Air Force does not anticipate changes to the geographic use, spectrum requirements, 

or time of usage for its system operating in the 1675-1695 MHz band. For the foreseeable 

future, the Air Force does not anticipate any relocation of systems from the band or 

 

53 Many of the receive stations in the 1685-1695 MHz band operate at the same location, so the number of spectrum 

usage contours shown in Appendix B are less than the number of receive stations shown in Table 7-3.
61

modifications that would impact the geographic usage, frequency/bandwidth requirements, or 

time usage for its system operating in the 1675-1695 MHz band.

8.3.3 Federal Access to Non-Federal Spectrum. DOC did not identify specific nonfederal frequency bands that could be used to satisfy its mission, but will work with NTIA and 

the FCC in analyzing non-federal bands that meet its technical and logistical requirements. 

8.3.4 Risks to Agency Mission Requirements. The signals from the DOC 

meteorological-satellites in the 1675-1695 MHz band are used by federal and non-federal 

entities. Since the non-federal users do not need to register or receive FCC authorization for 

their receive sites, data is not available to predict the impact of sharing with the non-federal users 

in the 1675-1695 MHz band.

54

 Many of the public safety uses are for mobile or transportable 

meteorological-satellite earth station receivers (e.g., EMWIN), for which it is not possible to 

establish geographic sharing arrangements. The impact to federal and non-federal users must be 

taken into account when considering sharing in the 1675-1695 MHz band. 

8.4 2700-2900 MHz Band

8.4.1 Total Spectrum Usage. Total Spectrum Usage in Table 7-4 shows the number of 

frequency assignments in the 5 megahertz band segments range from 42 to 157. Nine percent of 

the frequency assignments in this band authorize operation across the entire band.

55

 Based on 

the aggregation of the frequency usage data, and the criteria NTIA developed, no opportunities 

for frequency sharing in the 2700-2900 MHz band exist. The aggregate geographic usage 

component of Total Spectrum Usage shows that large percentages of the population can be 

impacted, ranging from 44.6 percent to as high as 74.7 percent across 5 megahertz band 

segments, as some systems have the flexibility to operate across the entire band (e.g., band 

assignments). The percentage of geographic area available ranged from 48.5 percent to 75.3

percent, across 5 megahertz band segments in the 2700-2900 MHz band. Based on the 

quantitative assessment data, and the criteria NTIA developed, geographic sharing opportunities 

in the 2700-2900 MHz band are limited. The ATC and NEXRAD radars support safety-of-life 

functions and are operating essentially 100 percent of the time, eliminating any potential 

opportunities for time sharing in the 2700-2900 MHz band.

8.4.2 Projections for Future Spectrum Usage. The FAA and the DOC have no plans 

to expand or terminate usage of the ASR and NEXRAD radar systems that operate in the 2700-

2900 MHz band. The FAA and DOC initially evaluated the feasibility of replacing the 

NEXRAD and ASR systems with a MPAR system in the 2700-3100 MHz frequency range. As 

stated in Section 1.4.2 and 1.4.4, the FAA and DOC effort has evolved into an ongoing

interagency activity that also includes DOD and DHS to develop plans to analyze the feasibility 

of relocating the aeronautical long-range radar systems from existing spectrum allocations, 

including the 1300-1350 MHz band, into the 2700-2900 MHz band as part of the SENSR 

capability. SENSR could facilitate interagency spectrum sharing in the 2700-3100 MHz 

 

54 Fast Track Report at 3-22.

55 In the GMF, a frequency assignment that authorizes operation of a system across the entire band is referred to as a 

band assignment.
62

frequency range and enable commercial broadband access in the 1300-1350 MHz band, based on 

the results of the feasibility study. Details of how the feasibility study will be conducted are still 

under development among the impacted federal agencies, including the determination of the 

SENSR spectrum requirements. The Army reported that at the present time it does not plan to 

design new systems in the 2700-2900 MHz band. Modifications to the existing systems will not 

require additional spectrum within the 2700-2900 MHz band. Based on the current information 

that is available, the Army anticipates that its present spectrum requirements in the 2700-2900 

MHz band are expected to remain unchanged.

The Navy and Marine Corps reported that they plan on continuing to operate systems in 

the 2700-2900 MHz band. It is anticipated that they will need additional frequencies in the band 

to support future operations. They also have plans to expand the geographic areas where their 

systems operate. The Navy and Marine Corps also expect that the time of usage for their 

systems will increase in the future. 

The Air Force does not anticipate changes to the geographic use, spectrum requirements, 

or time of usage for its systems operating in this band. For the foreseeable future, the Air Force 

does not anticipate any relocation of systems from the band or modifications that would impact 

the geographic usage, frequency/bandwidth requirements, or time usage for its systems operating 

in the 2700-2900 MHz band.

NASA has limited operations in the 2700-2900 MHz band that are anticipated to continue 

indefinitely. 

8.4.3 Federal Access to Non-Federal Spectrum. There are no non-federal ATC

systems in the 2700-2900 MHz frequency band that can aid the FAA in performing its mission. 

As for using existing operating systems and sharing data, the FAA currently shares system data 

from the NEXRAD weather radar systems operated by the DOC as well as data with radar 

systems operated by the DOD and DHS. The FAA currently shares data from the FAA systems 

with every other federal agency that can benefit from this data.

The federal agencies operating radar systems in the 2700-2900 MHz band did not 

identify non-federal frequency bands that could be used to aid in supporting their missions to 

perform ATC, weather prediction, and national security. 

8.4.4 Risks to Agency Mission Requirements. NEXRAD is used to warn the public 

about dangerous weather. 160 operational NEXRAD radar systems are deployed throughout the 

United States. Meteorologists use NEXRAD to provide severe weather and flash flood 

warnings; air traffic safety and flow control; resource protection at military bases; and 

management of water, agriculture, and forest resources. NEXRAD is critical to the DOC 

mission; therefore, harmful interference in the 2700-3000 MHz frequency band could impact the 

ability of the DOC to provide accurate weather information to the public. The potential loss of 

these essential mission requirements that can impact federal and non-federal users alike must be 

taken into account when considering the risks of sharing in this band to ensure current and future 

protection of these capabilities.
63

In general, non-radar (e.g., communication) systems and radar systems operated by the 

FAA in the 2700-2900 MHz frequency band are incompatible. The radar systems operated by 

the FAA provide aeronautical radionavigation and meteorological services that support safety-oflife applications (e.g., air traffic control operations within the national airspace system). 

Therefore, any risk of harmful interference is unacceptable. At this time, the FAA is not 

planning to make any changes to the mission requirements that the radar systems operating in 

this band support.

8.5 2900-3100 MHz Band

8.5.1 Total Spectrum Usage. Total Spectrum Usage in Table 7-5 shows that the 

number of frequency assignments for transmit stations in the 5 megahertz band segments, with 

the exception of the 2900-2905 MHz segment, ranges from 113 to 153. In this band, 52 percent 

of the frequency assignments authorize operations across the entire band. There are frequency 

assignments for shipborne transmit stations and US&P transmit stations in the band. Based on 

the aggregation of the frequency usage data, there are no opportunities for frequency sharing in 

the 2900-3100 MHz band. The aggregate geographic usage component of Total Spectrum Usage 

shows that the percentage of population impacted ranged from 42.8 percent to 64.5 percent. The 

US&P assignments are not represented in the geographic usage. The percentage of geographic 

area available ranged from 45.6 percent to 73.2 percent. Based on the quantitative assessment 

and the criteria NTIA developed, geographic sharing opportunities may exist in the 2900-3100 

MHz band, contingent upon the successful completion of a sharing feasibility study. In each of 

the 5 megahertz band segments, approximately half of the transmit stations have time of usage 

percentages ranging from 50 percent to 100 percent, limiting time sharing opportunities in the 

2900-3100 MHz band. Looking forward, a significant change in the quantitative assessment 

frequency and geographic usage data would occur if implementation of the SENSR capability in 

this band is found to be feasible, from a technical, operational, and cost perspective, as part of 

the relocation feasibility assessment of the 1300-1350 MHz band. 

8.5.2 Projections for Future Spectrum Usage. DOT’s MARAD has two frequency 

assignments in the 2900-3100 MHz band for radars operating on two Merchant Marine training 

vessels with the Merchant Marine Academy at Kings Point, New York. The 2900-3100 MHz 

band is used by federal and non-federal entities. There are no changes expected in the operation 

of the maritime radars for the foreseeable future in light of the non-federal usage of this band and 

the critical training mission they fulfill. For the foreseeable future, the maritime radars will 

continue to operate in the band, with no new systems or expansion of service anticipated. If 

equipment upgrades are needed, they will be off-the-shelf units as direct replacements.

DOT’s SLDSC has RACONs operating in the Saint Lawrence River in the 2900-3100 

MHz band. The 2900-3100 MHz band is used by both federal and non-federal users. No 

changes are expected in the service provided by these RACONs for the foreseeable future in 

light of the non-federal usage of this band and the critical nature of the operation of the 

RACONs. These RACONs will continue to operate in the band, with no new systems or 

expansion of service anticipated. If equipment upgrades are needed, they will be off-the-shelf 

units as direct replacements.
64

The Army reported that at the present time it does not plan to design new systems for the 

2900-3100 MHz band. Modifications to the existing systems will not require additional 

spectrum within the 2900-3100 MHz band. Based on the currently available information, the 

Army projects that its present spectrum requirements for the 2900-3100 MHz band are expected 

to remain unchanged.

The Navy and Marine Corps anticipates they will need additional frequencies in the band 

to support future operations. They also have plans to expand the geographic areas where their 

systems operate. The Navy and Marine Corps also expect that the time of usage for their 

systems will increase in the future. 

The Air Force does not anticipate changes to the geographic use, spectrum requirements, 

or time of usage for their systems operating in this band. For the foreseeable future, the Air 

Force does not anticipate any relocation of systems from the band or modifications that would 

impact the geographic usage, frequency/bandwidth requirements, or time usage for their systems 

operating in the 2900-3100 MHz band.

NASA, DOT, and DHS will continue to operate systems in the 2900-3100 MHz band for 

the foreseeable future. There are no plans for new systems or the expansion of existing systems. 

The geographic usage of this band will be impacted by the final disposition of the SENSR 

program through the ongoing and planned interagency evaluation of the feasibility of 

consolidating various radar systems from the 1300-1350 MHz and other bands into the 2700-

3100 MHz frequency range.

 

8.5.3 Federal Access to Non-Federal Spectrum. The federal agencies did not identify 

non-federal spectrum that could be used to fulfill their missions. 

8.5.4 Risks to Agency Mission Requirements. Meteorologists use NEXRAD to 

provide severe weather and flash flood warnings, air traffic safety and flow control; resource 

protection at military bases; and management of water, agriculture, and forest resources. 

NEXRAD is critical to the DOC mission; therefore, harmful interference in the 2700-3000 MHz 

frequency band could impact the ability of the DOC mission to provide accurate weather 

information to the public.

In general, non-radar (e.g., communication) systems and radar systems operated by the 

FAA in the 2900-3100 MHz frequency band are incompatible. The radar systems operated by 

the FAA in those frequency bands provide aeronautical radionavigation and meteorological 

services that support safety-of-life applications (e.g., air traffic control operations with the 

national airspace system). Therefore, any risk of harmful interference is unacceptable for the 

mission that the FAA performs. 

At this time the federal agencies have no plans to make changes to the mission 

requirements that the radar systems operating in the 2900-3100 MHz band support.
65

8.6 3100-3550 MHz Band

8.6.1 Total Spectrum Usage. Total Spectrum Usage in Table 7-5 shows that in the 

3100-3505 MHz portion of the band, the number of frequency assignments in the 5 megahertz 

band segments range from 0 to 68. In the 3505-3550 MHz portion of the band, the number of 

frequency assignments range in 5 megahertz band segments from 1 to 4. Thirty-three percent of

the frequency assignments in this band authorize operation across the entire band, recognizing 

that some systems have the capability to operate across the entire band (e.g., band assignments), 

recognizing that some systems have the capability to operate across the band. In addition, a 

small number of US&P frequency assignments can operate in segments of the band. Based on 

the aggregation of the frequency usage data, and the criteria NTIA developed, potential 

opportunities exist for frequency sharing, particularly in the 3505-3550 MHz portion of the band. 

The percentage of the population impacted ranged from 0 percent to 78.3 percent. The 

percentage of geographic area available ranged from 35.7 percent to 100 percent. Based on the 

quantitative assessment data and the criteria NTIA developed, geographic sharing opportunities

may exist, particularly in the upper 45 MHz portion of the band. In each of the 5 megahertz 

band segments, the transmit stations have usage percentages ranging from 1 percent to 10 

percent, indicating that time sharing opportunities may exist in the 3100-3550 MHz band. The 

sharing opportunities are contingent upon the successful completion of a feasibility study, which 

would take into account the US&P operations in the band. 

8.6.2 Projections for Future Spectrum Usage. The Army reported that at the present 

time, it does not plan to design new systems for the 3100-3550 MHz band. Modifications to the 

existing systems will not require additional spectrum within the 3100-3550 MHz band. The 

Army reported that one of its radars operating in this band may be deployed at additional 

locations in the United States. Based on the current available information, the Army projects 

that its present spectrum requirements in the 3100-3550 MHz band will remain unchanged.

The Navy and Marine Corps reported that they plan on continuing to operate systems in 

the 3100-3550 MHz band. It is anticipated that they will need additional frequencies in the band 

to support future operations. They also have plans to expand the geographic areas where their 

systems operate. The Navy and Marine Corps also expect that the time of usage for their 

systems will increase in the future. 

The Air Force does not anticipate changes to the geographic use, spectrum requirements, 

or time of usage for its systems operating in this band. For the foreseeable future, the Air Force 

does not anticipate any relocation of systems from the band or modifications that would impact 

the geographic usage, frequency/bandwidth requirements, or time usage for its systems operating 

in the 3100-3550 MHz band.

8.6.3 Federal Access to Non-Federal Spectrum. The DOD did not identify nonfederal spectrum that could be used to fulfill its missions. 

8.6.4 Risks to Agency Mission Requirements. The DOD’s air, land, maritime, and 

space operations increasingly depend on electromagnetic spectrum access. The growing 

requirements to gather, analyze, and share information rapidly; to control an increasing number 

of automated intelligence, surveillance, and reconnaissance assets; to command geographically 
66

dispersed and mobile forces; to gain access into denied areas; and to “train as they fight” requires 

that the DOD maintain sufficient spectrum access. In 2013, the DOD developed its 

Electromagnetic Spectrum Strategy that established a framework for how it should rapidly adapt 

to the changing spectrum environment and to assess and respond to spectrum regulatory 

changes.56 One of the objectives of its spectrum strategy is to accelerate the fielding of 

technologies that enable spectrum sharing access opportunities. The DOD will pursue promising 

technologies, establish policies, and adopt standards to improve interference mitigation while 

preserving the capabilities of its systems. The DOD also will identify systems that can share 

spectrum and/or operate compatibly with systems in adjacent spectrum bands without affecting 

system effectiveness or compromising operational safety.

 

56 Department of Defense Electromagnetic Spectrum Strategy, A Call to Action (2013).
APPENDICES

Appendix A SPECTRUM USAGE PLOTS: 1300-1390 MHZ BAND

Appendix B SPECTRUM USAGE PLOTS: 1675-1695 MHZ BAND

Appendix C SPECTRUM USAGE PLOTS: 2700-2900 MHZ BAND

Appendix D SPECTRUM USAGE PLOTS: 2900-3100 MHZ BAND

Appendix E SPECTRUM USAGE PLOTS: 3100-3550 MHZ BAND