Attachment Technical Narrative SES-LIC-20110209-00132

Attachment Technical Narrative

This document pretains to SES-LIC-20110209-00132 for License on a Satellite Earth Station filing.

IBFS_SESLIC2011020900132_868044

Technical Exhibit in Support of

General Dynamics SATCOM Technologies’
Vehicle-Mounted Earth Station License Application

Prepared for the

Federal Communications Commission

February 9, 2011

TABLE OF CONTENTS

1. Introduction................................................................................................................. 3
2. § 25.226 EIRP Spectral-Densities............................................................................... 3
2.1 General Dynamics Model 17 Terminal (M17) ................................................... 7
2.2 General Dynamics Model 20 Terminal (M20) ................................................... 8
2.3 General Dynamics Model 24 Terminal (M24) ................................................... 9
2.4 General Dynamics Model 30 Terminal (M30) ................................................. 10
3. Antenna Pointing and Control Functions.................................................................. 11
3.1 § 25.226 (a)(1)(ii) antenna pointing accuracy................................................... 11
3.2 § 25.226 (a)(1)(iii) cessation of emission requirements ................................... 17
3.3 § 25.226 (a)(4) contention protocol must be reasonable................................... 18
3.4 § 25.226 (a)(5) point of contact in the United States........................................ 19
3.5 § 25.226 (a)(6) VMES location logging ........................................................... 20
3.6 § 25.226 (a)(7) lack of protection from terrestrial stations............................... 20
3.7 § 25.226 (a)(8) limited protection in downlink bands ...................................... 21
3.8 § 25.226 (a)(9) VMES to automatically cease transmitting ............................. 21
4. VMES Coordination and Exclusion Zones............................................................... 22
4.1 § 25.226 (c) VMES protection for NASA TDRSS facilities ............................ 22
4.2 § 25.226 (d) VMES protection for Radio Astronomy Service facilities........... 23
4.3 § 25.226 (e) Global Positioning Satellite position location technology ........... 25

2

1. Introduction

General Dynamics SATCOM Technologies (“General Dynamics”), pursuant to 47 CFR §
25.226 of the Rules and Regulations (“Regulations”) of the Federal Communications
Commission (the “Commission”), respectfully requests the issuance of a new license to
operate a network of Vehicle-Mounted Earth Stations (“VMES”) throughout the United
States. The proposed VMES terminals will operate receiving in the 10.95-11.2 GHz
(space-to-Earth), 11.45-11.7 GHz (space-to-Earth), 11.7-12.2 GHz (space-to-Earth) Ku-
Band frequencies and transmit in the 14.0-14.5 GHz (Earth-to-space) Ku-Band
frequencies with Geostationary Satellites in the Fixed-Satellite Service. The proposed
VMES terminals will communicate with already licensed hub stations located in the
United States.1

The proposed VMES terminals consist of a variety of different antenna apertures
intended to satisfy a range of potential broadband VMES communications requirements.
They include:

- General Dynamics Model 17 Terminal (M17) 50 systems

- General Dynamics Model 20 Terminal (M20) 50 systems

- General Dynamics Model 24 Terminal (M24) 50 systems

- General Dynamics Model 30 Terminal (M30) 50 systems

The VMES manufacturer is General Dynamics. Each of the VMES terminals utilizes a
pointing and tracking system-stabilized antenna to communicate with FSS Ku-Band
satellites. Due to their respective sizes, the VMES antennas themselves do not strictly
comply with § 25.209 of the Commission’s Rules. However through the use of very
precise antenna pointing and tracking, combined with careful EIRP power spectral-
density control, General Dynamics will fully comply with the requirements specified in
§ 25.226 paragraph (a)(1).2 In the instant exhibit, General Dynamics demonstrates full
compliance with the VMES Regulations set forth below.

2. § 25.226 EIRP Spectral-Densities

From § 25.226 (a), “…VMES licensees shall comply with the requirements in either
paragraph (a)(1), (a)(2) or (a)(3) of this section and all of the requirements set forth in
paragraphs (a)(4)-(a)(9) and paragraphs (c), (d), and (e) of this section. Paragraph (b)

1
File No 0111-EX-RR-2009.
2
Thus, pursuant to Question 35 (“Basic Qualifications”) in the 312 Main Form, General Dynamics
requests waiver of the antenna performance standards set forth in § 25.209 of the Commission’s Rules only
to the extent such a waiver is required. General Dynamics respectfully submits that such a waiver, if
required, serves the public interest by contributing to the achievement of communications that are critical to
essential domestic emergency response applications as well as tactical communications requirements for
the U.S. military operating in the U.S. and around the world.

3

of this section identifies items that shall be included in the application for VMES
operations to demonstrate that these ongoing requirements will be met.”

The proposed VMES system complies with paragraph (a)(1) in that the EIRP spectral-
density limits are complied with in all directions -- both in the GSO plane and in all
directions other than along the GSO plane. Additionally, the proposed VMES antennas
are circular, so paragraph (a)(1)(i)(D) does not apply—the off-axis EIRP spectral-density
criteria are satisfied in all antenna orientations.

From § 25.226 (a)(1), “The following requirements shall apply to a VMES that uses
transmitters with off-axis EIRP spectral-densities lower than or equal to the levels in
paragraph (a)(1)(i) of this subsection. A VMES or VMES system, operating under this
subsection shall provide a detailed demonstration as described in paragraph (b) (1) of
this section. The VMES transmitter also shall comply with the antenna pointing and
cessation of emission requirements in paragraphs (a)(1)(ii) and (a)(1)(iii) of this
subsection.

(i) A VMES system shall not exceed the off-axis EIRP spectral-density limits and
conditions defined in paragraphs (a)(1)(A)-(D) of this subsection.

(A) The off-axis EIRP spectral-density emitted from the VMES, in the plane of the
geostationary satellite orbit (GSO) as it appears at the particular earth station
location, shall not exceed the following values:

15 - 10log(N) - 25logθ dBW/4 kHz for 1.5° ≤ θ ≤ 7°
-6 -10log(N) dBW/4 kHz for 7° < θ ≤ 9.2°
18 -10log(N) - 25logθ dBW/4 kHz for 9.2° < θ ≤ 48°
-24 -10log(N) dBW/4 kHz for 48° < θ ≤ 85°
-14 -10log(N) dBW/4 kHz for 85° < θ ≤ 180°

where theta (θ) is the angle in degrees from the line connecting the focal point of
the antenna to the orbital location of the target satellite, the plane of the GSO is
determined by the focal point of the antenna and the line tangent to the arc of the
GSO at the orbital location of the target satellite. For VMES networks using
frequency division multiple access (FDMA) or time division multiple access
(TDMA) techniques, N is equal to one. For VMES networks using multiple co-
frequency transmitters that have the same EIRP, N is the maximum expected
number of co-frequency simultaneously transmitting VMES earth stations in the
same satellite receiving beam. For the purpose of this subsection, the peak EIRP
of an individual sidelobe shall not exceed the envelope defined above for θ
between 1.5° and 7.0°. For θ greater than 7.0°, the envelope shall be exceeded by
no more than 10% of the sidelobes, provided no individual sidelobe exceeds the
envelope given above by more than 3 dB.

4

(B) In all directions other than along the GSO, the off-axis EIRP spectral-density
for co-polarized signals emitted from the VMES shall not exceed the following
values:

18 - 10log(N) - 25logθ dBW/4 kHz for 3.0° ≤ θ ≤ 48°
-24 - 10log(N) dBW/4 kHz for 48° < θ ≤ 85°
-14 - 10log(N) dBW/4kHz for 85° < θ ≤ 180°

where θ and N are defined in (a)(1)(i)(A). This off-axis EIRP spectral-density
applies in any plane that includes the line connecting the focal point of the
antenna to the orbital location of the target satellite with the exception of the
plane of the GSO as defined in paragraph (a)(1)(i)(A) of this section. For the
purpose of this subsection, the envelope shall be exceeded by no more than 10%
of the sidelobes provided no individual sidelobe exceeds the gain envelope given
above by more than 6 dB. The region of the main reflector spillover energy is to
be interpreted as a single lobe and shall not exceed the envelope by more than 6
dB.

(C) In all directions, the off-axis EIRP spectral-density for cross-polarized signals
emitted from the VMES shall not exceed the following values:

5 - 10log(N) - 25logθ dBW/4 kHz for 1.8° ≤ θ ≤ 7.0°
-16 - 10log(N) dBW/4 kHz for 7.0° < θ ≤ 9.2°

where θ and N are defined as set forth in paragraph (a)(1)(i)(A) of this section.
This EIRP spectral-density applies in any plane that includes the line connecting
the focal point of the antenna to the target satellite.
(D) For non-circular VMES antennas, the major axis of the antenna shall be
aligned with the tangent to the arc of the GSO at the orbital location of the target
satellite, to the extent required to meet the specified off-axis EIRP spectral-density
criteria.”

The proposed VMES terminals consist of four different antenna apertures intended to
satisfy a range of potential broadband VMES communications requirements. The four
antenna apertures include:

a. General Dynamics Model 17 Terminal (M17) – approximately 17 inches in
diameter

b. General Dynamics Model 20 Terminal (M20) – approximately 20 inches in
diameter

c. General Dynamics Model 24 Terminal (M24) – approximately 24 inches in
diameter

5

d. General Dynamics Model 30 Terminal (M30) – approximately 30 inches in
diameter

§ 25.226 (b)(1) provides, in relevant part, that “[a] VMES applicant proposing to
implement a transmitter under paragraph (a)(1) of this section shall demonstrate that the
transmitter meets the off-axis EIRP spectral-density limits contained in paragraph
(a)(1)(i) of this section. To provide this demonstration, the application shall include the
tables described in paragraph (b)(1)(i) of this section … . The VMES applicant also shall
provide the value N described in paragraph (a)(1)(i)(A) of this section.”

(i) Any VMES applicant filing an application pursuant to paragraph (a)(1) of this
section shall file three tables showing the off-axis EIRP level of the proposed earth
station antenna in the direction of the plane of the GSO; the co-polarized EIRP in the
elevation plane, that is, the plane perpendicular to the plane of the GSO; and cross-
polarized EIRP. Each table shall provide the EIRP level at increments of 0.1° for
angles between 0° and 10° off-axis, and at increments of 5° for angles between 10°
and 180° off-axis.

(A) For purposes of the off-axis EIRP table in the plane of the GSO, the off-axis
angle is the angle in degrees from the line connecting the focal point of the
antenna to the orbital location of the target satellite, and the plane of the GSO is
determined by the focal point of the antenna and the line tangent to the arc of the
GSO at the orbital position of the target satellite.

(B) For purposes of the off-axis co-polarized EIRP table in the elevation plane,
the off-axis angle is the angle in degrees from the line connecting the focal point
of the antenna to the orbital location of the target satellite, and the elevation
plane is defined as the plane perpendicular to the plane of the GSO defined in
paragraph (b) (1) (i) (A) of this section.

(C) For purposes of the cross-polarized EIRP table, the off-axis angle is the angle
in degrees from the line connecting the focal point of the antenna to the orbital
location of the target satellite and the plane of the GSO as defined in paragraph
(b)(1)(i)(A) of this section will be used”.

Radiation patterns, in accordance with the requirements of § 25.226 paragraph (b)(1) are
provided here for each of the proposed antenna apertures.

6

2.1 General Dynamics Model 17 Terminal (M17)

The General Dynamics Model 17 Terminal utilizes an antenna aperture which is circular
and is approximately 17-inches in diameter. To ensure that the EIRP spectral-density
limits prescribed in § 25.226 paragraph (a)(1) are satisfied, the Model 17 input power
spectral-density is limited to -23.0 dbW/4 kHz. This results in the following EIRP
spectral-density performance:

Off-axis EIRP level of the proposed earth station antenna in the direction of the plane of
the GSO.
EIRP Spectral Density. VMES Co Polar EIRP Spectral Density. VMES Co Polar
15 H-plane 15 H-plane

5
5

EIRP Density, dBW/4KHz
EIRP Density, dBW/4KHz

-5
-5
-15
-15
-25

-25
-35

-35 -45
-20 -15 -10 -5 0 5 10 15 20 -180 -140 -100 -60 -20 20 60 100 140 180
ANGLE, deg ANGLE, deg

Figure 2.1.1 M17 Off-Axis EIRP in the plane of the GSO (Azimuth or H-plane)

Co-polarized EIRP in the elevation plane, that is, the plane perpendicular to the plane of
the GSO.
EIRP Spectral Density. VMES Co Polar EIRP Spectral Density. VMES Co Polar
15 15
E-plane E-plane

5 5
EIRP Density, dBW/4KHz
EIRP Density, dBW/4KHz

-5
-5
-15
-15
-25

-25 -35

-35 -45
-20 -15 -10 -5 0 5 10 15 20 -180 -140 -100 -60 -20 20 60 100 140 180
ANGLE, deg ANGLE, deg

Figure 2.1.2 M17 Off-Axis EIRP in the plane perpendicular to GSO (elevation or E-plane)

Cross-polarized EIRP in the plane of the GSO.
EIRP Spectral Density. VMES Co Polar EIRP Spectral Density. VMES Co Polar
15 H-plane 15 H-plane

5
EIRP Density, dBW/4KHz
EIRP Density, dBW/4KHz

5

-5
-5
-15
-15
-25

-25
-35

-35 -45
-20 -15 -10 -5 0 5 10 15 20 -180 -140 -100 -60 -20 20 60 100 140 180
ANGLE, deg ANGLE, deg

Figure 2.1.3 M17 Off-Axis Cross-Polarized EIRP in the plane of the GSO
(Azimuth or H-plane)

7

2.2 General Dynamics Model 20 Terminal (M20)

The General Dynamics Model 20 Terminal utilizes an antenna aperture which is circular
and is approximately 20-inches in diameter. To ensure that the EIRP spectral-density
limits prescribed in § 25.226 paragraph (a)(1) are satisfied, the Model 20 input power
spectral-density is limited to -23.0 dbW/4 kHz. This results in the following EIRP
spectral-density performance:

Off-axis EIRP level of the proposed earth station antenna in the direction of the plane of
the GSO.
EIRP Spectral Density. VMES Co Polar EIRP Spectral Density. VMES Co Polar
15
15 H-plane H-plane

5

EIRP Density, dBW/4KHz
5
EIRP Density, dBW/4KHz

-5
-5
-15

-15
-25

-25
-35

-35 -45
-20 -15 -10 -5 0 5 10 15 20 -180 -140 -100 -60 -20 20 60 100 140 180
ANGLE, deg ANGLE, deg

Figure 2.2.1 M20 Off-Axis EIRP in the plane of the GSO (Azimuth or H-plane)

Co-polarized EIRP in the elevation plane, that is, the plane perpendicular to the plane of
the GSO.
EIRP Spectral Density. VMES Co Polar EIRP Spectral Density. VMES Co Polar
15 15
E-plane E-plane

5
5
EIRP Density, dBW/4KHz

EIRP Density, dBW/4KHz

-5
-5
-15
-15
-25

-25
-35

-35 -45
-20 -15 -10 -5 0 5 10 15 20 -180 -140 -100 -60 -20 20 60 100 140 180
ANGLE, deg ANGLE, deg

Figure 2.2.2 M20 Off-Axis EIRP in the plane perpendicular to GSO (elevation or E-plane)

Cross-polarized EIRP in the plane of the GSO.
EIRP Spectral Density. VMES Cross Polar EIRP Spectral Density. VMES Cross Polar
15 15
H-plane H-plane

5
5
EIRP Density, dBW/4KHz

EIRP Density, dBW/4KHz

-5
-5
-15
-15
-25

-25
-35

-35 -45
-20 -15 -10 -5 0 5 10 15 20 -180 -140 -100 -60 -20 20 60 100 140 180
ANGLE, deg ANGLE, deg

Figure 2.2.3 M20 Off-Axis Cross-Polarized EIRP in the plane of the GSO
(Azimuth or H-plane)

8

2.3 General Dynamics Model 24 Terminal (M24)

The General Dynamics Model 24 Terminal utilizes an antenna aperture which is circular
and is approximately 24-inches in diameter. To ensure that the EIRP spectral-density
limits prescribed in § 25.226 paragraph (a)(1) are satisfied, the Model 24 input power
spectral-density is limited to -23.0 dbW/4 kHz. This results in the following EIRP
spectral-density performance:

Off-axis EIRP level of the proposed earth station antenna in the direction of the plane of
the GSO.
EIRP Spectral Density. VMES Co Polar EIRP Spectral Density. VMES Co Polar
15 H-plane 15 H-plane

5

EIRP Density, dBW/4KHz
EIRP Density, dBW/4KHz

5

-5
-5
-15

-15
-25

-25 -35

-45
-35
-180 -140 -100 -60 -20 20 60 100 140 180
-20 -15 -10 -5 0 5 10 15 20
ANGLE, deg
ANGLE, deg

Figure 2.3.1 M24 Off-Axis EIRP in the plane of the GSO (Azimuth or H-plane)

Co-polarized EIRP in the elevation plane, that is, the plane perpendicular to the plane of
the GSO.
EIRP Spectral Density. VMES Co Polar EIRP Spectral Density. VMES Co Polar
15 E-plane 15 E-plane

5
EIRP Density, dBW/4KHz

5
EIRP Density, dBW/4KHz

-5
-5
-15
-15
-25

-25 -35

-35 -45
-20 -15 -10 -5 0 5 10 15 20 -180 -140 -100 -60 -20 20 60 100 140 180

ANGLE, deg ANGLE, deg

Figure 2.3.2 M24 Off-Axis EIRP in the plane perpendicular to GSO (elevation or E-plane)

Cross-polarized EIRP in the plane of the GSO.
EIRP Spectral Density. VMES Cross Polar EIRP Spectral Density. VMES Cross Polar
15 15
H-plane H-plane

5
5
EIRP Density, dBW/4KHz

EIRP Density, dBW/4KHz

-5
-5
-15
-15
-25

-25
-35

-35 -45
-20 -15 -10 -5 0 5 10 15 20 -180 -140 -100 -60 -20 20 60 100 140 180
ANGLE, deg ANGLE, deg

Figure 2.3.3 M24 Off-Axis Cross-Polarized EIRP in the plane of the GSO
(Azimuth or H-plane)

9

2.4 General Dynamics Model 30 Terminal (M30)

The General Dynamics Model 30 Terminal utilizes an antenna aperture which is circular
and is approximately 30-inches in diameter. To ensure that the EIRP spectral-density
limits prescribed in § 25.226 paragraph (a)(1) are satisfied, the Model 30 input power
spectral-density is limited to -23.0 dbW/4 kHz. This results in the following EIRP
spectral-density performance:

Off-axis EIRP level of the proposed earth station antenna in the direction of the plane of
the GSO.
EIRP Spectral Density. VMES Co Polar EIRP Spectral Density. VMES Co Polar
20 15
H-plane H-plane

5
10
EIRP Density, dBW/4KHz

EIRP Density, dBW/4KHz
-5
0
-15
-10
-25

-20
-35

-30 -45
-20 -15 -10 -5 0 5 10 15 20 -180 -140 -100 -60 -20 20 60 100 140 180
ANGLE, deg ANGLE, deg

Figure 2.4.1 M30 Off-Axis EIRP in the plane of the GSO (Azimuth or H-plane)

Co-polarized EIRP in the elevation plane, that is, the plane perpendicular to the plane of
the GSO.
EIRP Spectral Density. VMES Co Polar EIRP Spectral Density. VMES Co Polar
20 15
E-plane E-plane

5
10
EIRP Density, dBW/4KHz
EIRP Density, dBW/4KHz

-5
0
-15

-10
-25

-20 -35

-45
-30
-180 -140 -100 -60 -20 20 60 100 140 180
-20 -15 -10 -5 0 5 10 15 20
ANGLE, deg ANGLE, deg

Figure 2.4.2 M30 Off-Axis EIRP in the plane perpendicular to GSO (elevation or E-plane)

Cross-polarized EIRP in the plane of the GSO.
EIRP Spectral Density. VMES Cross Polar EIRP Spectral Density. VMES Cross Polar
15 15
H-plane H-plane

5
5
EIRP Density, dBW/4KHz

EIRP Density, dBW/4KHz

-5
-5
-15
-15
-25

-25
-35

-35 -45
-20 -15 -10 -5 0 5 10 15 20 -180 -140 -100 -60 -20 20 60 100 140 180
ANGLE, deg ANGLE, deg

Figure 2.4.3 M30 Off-Axis Cross-Polarized EIRP in the plane of the GSO
(Azimuth or H-plane)

10

In practice, General Dynamics has confirmed that by transmitting a CW signal from a
VMES terminal towards a desired satellite permits the downlink signals from both the
desired satellite an adjacent satellite to be measured using appropriately large downlink
receiving earth stations pointed towards the two satellites.

The antenna pointing accuracy test procedure used in measurement is as follows:

1. The VMES terminal under test radiates a CW tone on a desired test frequency
towards the target satellite. The amplitude of the transmitted CW tone should be
carefully adjusted to the exact level at which the calculated EIRP spectral density
towards the adjacent satellite is precisely at the FCC-mandated adjacent satellite
EIRP spectral density limit.

2. Once the VMES terminal is confirmed to be transmitting the desired uplink
EIRP CW signal level, the downlink measurement apparatus can be calibrated.
This calibration is achieved through a multi-step process:

a. Peak the downlink receive earth terminals on both the target satellite and the
adjacent satellite.

b. Set the center frequency of Tracking Receiver 1 and Tracking Receiver 2 to
the desired downlink Center Frequency, which will result in the downlink
signals being measured on the Tracking Receiver tracking output signal line.

c. Ensure that the measurement dual-trace oscilloscope or dual-channel ADC is
measuring Tracking Signal levels in an acceptable range.

d. Confirm that the entire system is operating in the linear range of all
subsystems and components.

3. An angle calibration process is then performed. If space segment is available on
two adjacent satellites, and intentional radiations in excess of the nominal permitted
adjacent satellite signal levels are permitted, the measurements can be taken on the
desired and adjacent satellites using an initial “angle calibration” test run. With this
approach, the measurement equipment is set up and calibrated and then the VMES
antenna under test is intentionally stepped from the desired satellite to the adjacent
satellite. Resultant C or (C+N) levels are then measured and recorded at each step
along the movement of the VMES antenna under test which can serve as an
absolute calibration of the true angular offset. This approach can provide optimal
measurement results because higher (C+N) signal levels can be utilized on the
adjacent satellite. It also eliminates any need to rely upon previously-measured or
theoretical antenna pattern data because the measurement data collected in the
calibration run reflects any antenna pattern or terminal factors which might affect
the signal levels on both the desired and adjacent satellites. It was this approach

14

that the tests conducted on August 4. 2010 represent the true antenna pointing and
tracking performance that can be anticipated for each of the different General Dynamics
VMES terminals.

The VMES antenna pointing and tracking tests performed on August 4, 2010, were
conducted with the following conditions:

Target Satellite: AMC-4

Adjacent satellite: AMC-1

Uplink frequency: 14.243 GHz

Test location: vicinity of Kilgore, Texas

Weather conditions during the test: clear skies

The results of the antenna pointing and tracking test confirmed that the Model 20 VMES
antenna did, in fact, demonstrate a pointing error of less than 0.2 degrees along the
geostationary arc during the complete test period. Tracking error measurements are
represented graphically in Figure 3.4
Resultant Pointing Error
1

0.8

0.6
Antenna stationary
0.4 from 300 seconds on.

0.2
This section of data not
used in error analysis.
Degrees

0

-0.2

-0.4

-0.6

-0.8

-1
50 100 150 200 250 300 350 400 450
Time(Seconds)

Figure 3.4 Measured Pointing Error

As both a confirmation that the test equipment used in the measurement system was
functioning properly and to confirm that potential error contributions did not adversely
impact the measurement results, General Dynamics examined the angular “errors”
measured while the antenna was completely stationary. As shown in the test data in
Figure 3.4 above, the data from the period 300 seconds into the test until the end of the
test represent measurements made while the VMES antenna and vehicle were completely

16

stable and remained fix-pointed at the satellite of interest. The measured error during that
period represents the “noise” in the measurement system as deviating from ideal
measurement results. It can clearly be attributed to both atmospheric noise as well as
electrical noise in the complete satellite signal link from the VMES CW uplink to the two
downlink measurement tracking receivers.

3.2 § 25.226 (a)(1)(iii) cessation of emission requirements

From § 25.226 (a)(1)(iii), “Each VMES transmitter shall meet one of the following
cessation of emission requirements:

(A) For VMESs operating under paragraph (a)(1)(ii)(A) of this section, all emissions
from the VMES shall automatically cease within 100 milliseconds if the angle
between the orbital location of the target satellite and the axis of the main lobe of the
VMES antenna exceeds 0.5°, and transmission shall not resume until such angle is
less than or equal to 0.2° … ”

General Dynamics has designed the proposed VMES terminals with an Antenna Pointing
and Tracking system that makes use of a closed-loop servo system as described in
Section 3.1 above. As part of its antenna pointing function, the Antenna Pointing and
Tracking system mutes the uplink transmitter to satisfy the cessation of emission
requirement as necessary. This functionality is provided in the following way:

a. The proposed VMES terminals utilize a GPS receiver to determine the
location of the VMES terminal itself. The GPS-derived location information
is updated on the order of every few seconds and is not critical to accurate
antenna pointing. (In fact, the most critical function of this GPS-derived
location information is for initial acquisition of the satellite signal.) Once the
VMES terminal is in normal operation, the satellite antenna look angle
information is constantly updated through the closed-loop servo system and
any long-term drift is corrected out.

b. The Inertial Reference Unit used by the VMES terminals provides constantly-
updated information on the verticality, velocity, and acceleration of the VMES
terminal platform. The VMES Inertial Reference Unit must provide accurate
measurements of the VMES terminal’s attitude at a exceedingly short time
intervals to permit calculation of the intended antenna look angles so that this
angle can be compared with the measured antenna look angles. In practice,
the VMES Inertial Reference Unit used by General Dynamics provides
attitude information to an accuracy on the order of 0.01 degrees at an interval
between measurements of not more than approximately 20 milliseconds.
Additionally, the velocity and acceleration information reported by the Inertial
Reference Unit is utilized by the closed-loop servo system to refine the
antenna position drive commands based upon movement of the VMES
antenna platform.

17

c. Sensors mounted on the VMES antenna and pedestal itself accurately measure
antenna pointing angles relative to the VMES mounting platform, antenna
velocities, and antenna accelerations. The position sensors measure antenna
pointing angles in azimuth, elevation, and polarization, to an accuracy of less
than approximately 0.01 degrees and this information is incorporated in the
Antenna Control Unit antenna angle calculations at an interval between
calculations of not more than approximately 20 milliseconds.

Utilizing these inputs, the VMES Antenna Control Unit ensures that transmissions are
interrupted if the VMES antenna pointing error exceeds 0.5 degrees and does not restore
transmissions until VMES antenna pointing error is again less than or equal to 0.2
degrees. The RF transceiver mounted on the rear of the VMES antenna is directly
commanded by the VMES Antenna Control Unit to mute the transmitter. This is
accomplished by muting the actual uplink Solid State Power Amplifier (“SSPA”) and can
be achieved in less than 10 milliseconds.

Effective implementation of this emission cessation function relies upon two critical
factors. First, the transmitter mute function itself must be capable of responding to
system commands in a period much less than 100 milliseconds. Field tests confirm that
the transmit power amplifier mute function as implemented by General Dynamics can be
performed in a sufficiently short time period that the muting is assured to be performed in
much less than 100 milliseconds. Secondly, the reference by which it is determined that
antenna pointing is in error must be sufficiently accurate to ensure that pointing errors on
the order of 0.1 degrees can be observed. Field testing of General Dynamics’ VMES
terminals described in Section 3.1 above, completely independent of the antenna pointing
angles reported by the VMES itself, confirm that the calculations of antenna pointing
angles match observed antenna pointing angles to an accuracy much better than 0.1
degrees.

Thus, General Dynamics confirms that the proposed VMES terminals contain
functionality which will mute the uplink transmitter and ensure that emissions cease if
antenna pointing errors exceed 0.5 degrees and that emissions will not resume until
antenna pointing errors are confirmed to be less than or equal to 0.2 degrees.

3.3 § 25.226 (a)(4) contention protocol must be reasonable

From § 25.226 (a)(4) “An applicant filing to operate a VMES terminal or system and
planning to use a contention protocol shall certify that its contention protocol use will
be reasonable”

The VMES terminals proposed by General Dynamics in the instant license application
utilize versions of the ViaSat Linkway VSAT system modems. These modems are
produced by ViaSat and have provided successful VSAT services on FSS Ku-Band
systems for several years. Their signal structure is based on fairly typical VSAT
modulation with time slots assigned in the network by a designated network control
station. Communication for the purposes of time slot coordination are conducted in a

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single contention-based burst within the TDMA frame, called the signaling burst (SB).
The SB contention protocol is slotted ALOHA -- the most widely known and studied
random access protocol -- which used by the majority of VSAT TDMA network
modems.

The Linkway TDMA frame time is 27 ms. In each TDMA frame the SB sub-frame, for a
10 MSPS carrier for example, is 0.31 ms. Using the slotted ALOHA contention protocol,
each VMES terminal attempting to communicate on the SB would synchronize with the
control station burst timing prior requesting access. Following the request for access to
the network control terminal, network traffic is then assigned within the TDMA burst
structure in a traffic slot so only the request need be transmitted in the SB, reducing the
total amount of traffic and thus contention for SB sub-frame resources. Within the SB
sub-frame, collisions are only expected when multiple VMES station modems request a
time slot simultaneously; and most slots will have already been assigned outside of the
SB sub-frame. Thus, the probability of signal collisions within the SB sub-frame is very
low and easily supports the theoretical capacity of 0.38 of the available SB
communications capacity.

Using this slotted ALOHA technique, as an implementation of the most widely used
VSAT contention protocol, General Dynamics certifies that the contention protocol used
is reasonable.

3.4 § 25.226 (a)(5) point of contact in the United States

From § 25.226 (a) (5) “There shall be a point of contact in the United States, with phone
number and address, available 24 hours a day, seven days a week, with authority and
ability to cease all emissions from the VMESs.”

When in operation, the proposed VMES terminals will be in continuous contact with the
ViaSat Network Operations Center. This facility can be contacted 24 hours a day, seven
days a week, and has full authority to remotely command transmissions to cease from any
and all VMES terminals in the network.

The network control contact information is:

ViaSat Network Operations Center Duty Officer
Telephone: 888 272-7232
Email: noc-carlsbad@viasat.com
Address: 6155 El Camino Real
Carlsbad, CA 92009

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3.5 § 25.226 (a)(6) VMES location logging

From § 25.226 (a)(6) “For each VMES transmitter, a record of the vehicle location (i.e.,
latitude/longitude), transmit frequency, channel bandwidth and satellite used shall be
time annotated and maintained for a period of not less than one (1) year. Records
shall be recorded at time intervals no greater than every five (5) minutes while the
VMES is transmitting. The VMES operator shall make this data available upon
request to a coordinator, fixed system operator, fixed-satellite system operator, NTIA,
or the Commission within 24 hours of the request.”

When in operation, the proposed VMES terminals will continuously determine their
location through the use of GPS receivers installed in each VMES. The location
information will be reported to the proposed VMES network control facility and recorded
at time intervals not to exceed five (5) minutes whenever the VMES is transmitting.
Additionally, each VMES will report to the Network Control Facility the time any
transmissions begin. The Network Control Facility will additionally record the time any
VMES transmissions cease, or, in default if communications are lost, the time of the last
VMES transmission heard from each VMES terminal. The network control facility will
record the VMES identification information in addition to the following information:

- Time stamp for each data entry
- VMES location in terms of latitude and longitude

For each set of data, and until it is changed for any VMES, the following information will
also be recorded by the Network Control Facility:

- Transmit (uplink) frequency
- Transmit channel bandwidth and modulation characteristics
- VMES EIRP limit referenced to the Network Control Facility
- Satellite used

The data records collected by the Network Control Facility in connection with the
proposed VMES operations will be maintained for a period of not less than 12 months,
and typically 18 months,. The VMES data will be made available upon request to a
coordinator, fixed system operator, fixed-satellite system operation, NTIA, or the Federal
Communications Commission within 24 hours of a request via telephone, email, or postal
mail made to the Network Control Facility listed in the previous section.

3.6 § 25.226 (a)(7) lack of protection from terrestrial stations

General Dynamics fully understands and agrees that the VMES operation proposed under
this application will not claim and will not receive protection from any authorized
terrestrial stations to which frequencies are either already assigned (or may be assigned in
the future) in the frequency bands of 10.95-11.2 GHz and 11.45-11.7 GHz. Testing
conducted under an Experimental Authorization by General Dynamics has confirmed that

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5) Thus cessation of VMES transmissions due to loss of downlink signal as
determined by the tracking receiver requires a total of approximately 57
milliseconds, maximum.

In addition to the tracking receiver mute function, the proposed VMES terminals also
continuously monitor the traffic downlink signal, which is also called the “out-route”
signal in VSAT operating terms. The modem system utilized by the proposed VMES
terminals utilizes a version of the standard ViaSat Linkway VSAT network modem
hardware supporting a Time-Division Multiplex (TDM) out-route signal and a Time-
Division Multiple Access (TDMA) uplink or in-route modulation scheme. The ViaSat
Linkway modem continuously receives both traffic and control information via
demodulation of the out-route signal. As a standard feature of these modems, the
modems themselves will command the transmitter to mute transmissions if the out-route
carrier cannot be effectively demodulated, indicating either loss of the out-route
transmissions themselves or excessive attenuation on the downlink from the out-route
transmission. Muting is accomplished by canceling the next uplink TDMA burst, which
is all accomplished within the modem itself and does not rely upon external inputs from
the tracking receiver or external commands issued to the SSPA. Effective uplink muting
is accomplished using this method in a time period of typically less than 10 milliseconds.

4. VMES Coordination and Exclusion Zones

4.1 § 25.226 (c) VMES protection for NASA TDRSS facilities

From § 25.226 (c), “(1) Operations of VMESs in the 14.0-14.2 GHz (Earth-to-space)
frequency band within 125 kms of the NASA TDRSS facilities on Guam (latitude 13° 36'
55'' N, longitude 144° 51' 22'' E) or White Sands, New Mexico (latitude 32° 20' 59'' N,
longitude 106° 36' 31'' W and latitude 32° 32' 40'' N, longitude 106° 36' 48'' W) are
subject to coordination with the National Aeronautics and Space Administration (NASA)
through the National Telecommunications and Information Administration (NTIA)
Interdepartment Radio Advisory Committee (IRAC). Licensees shall notify the
International Bureau once they have completed coordination. Upon receipt of such
notification from a licensee, the International Bureau will issue a public notice stating
that the licensee may commence operations within the coordination zone in 30 days if no
party has opposed the operations.

(2) When NTIA seeks to provide similar protection to future TDRSS sites that
have been coordinated through the IRAC Frequency Assignment Subcommittee process,
NTIA will notify the Commission’s International Bureau that the site is nearing
operational status. Upon public notice from the International Bureau, all Ku-band
VMES licensees shall cease operations in the 14.0-14.2 GHz band within 125 kms of the
new TDRSS site until the licensees complete coordination with NTIA/IRAC for the new
TDRSS facility. Licensees shall notify the International Bureau once they have
completed coordination for the new TDRSS site. Upon receipt of such notification from a
licensee, the International Bureau will issue a public notice stating that the licensee may
commence operations within the coordination zone in 30 days if no party has opposed the

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operations. The VMES licensee then will be permitted to commence operations in the
14.0-14.2 GHz band within 125 kms of the new TDRSS site, subject to any operational
constraints developed in the coordination process.”

The proposed VMES terminals utilize a GPS receiver to determine the location of the
VMES terminal itself, as described in paragraph 3.2.a above. The GPS-derived location
information is updated on the order of every few seconds and is not critical to accurate
antenna pointing. This same GPS-derived location information is used to ensure that the
VMES terminals satisfy the geographic operational coordination and exclusion zone
requirements.

The VMES terminals utilize a Monitor & Control processor in conjunction with the
VMES Antenna Control Unit for operator interface with the terminals. The VMES
Monitor & Control processor provides the facility for the VMES operator to control
normal VMES functions such as designation of the intended satellite, entering satellite
ephemeris data, transmitter activation and muting, uplink power measurement and
control, etc. To ensure proper geographic coordination and exclusion operation, the
VMES Monitor & Control system continuously compares the determined VMES location
information with the regions within 125 kms of the NASA TDRSS facilities on Guam
and in White Sands, New Mexico. When the Commission specifies that protection will
be provided to future TDRSS sites, the location of those sites will also be programmed
into the VMES Monitor & Control system for similar comparison to ensure protection.

The VMES Monitor & Control system will normally mute the transmitter if the terminal
is determined to be within any of the TDRSS coordination zones. A special password-
protected feature, only available to VMES system administrators and not available to
normal VMES terminal operators, is provided to override the geographic coordination
zone transmitter mute function for those cases where the required coordination has
successfully been accomplished. Proper operation of this transmitter mute functionality
can be ensured through both local reporting to the VMES operator via the Monitor &
Control system as well as via the remote location logging which is reported to the VMES
network control facility and continuously logged there.

4.2 § 25.226 (d) VMES protection for Radio Astronomy Service facilities

From § 25.226 (d), “(1) Operations of VMESs in the 14.47-14.5 GHz (Earth-to-space)
frequency band in the vicinity of radio astronomy service (RAS) observatories observing
in the 14.47-14.5 GHz band are subject to coordination with the National Science
Foundation (NSF). The appropriate NSF contact point to initiate coordination is
Electromagnetic Spectrum Manager, NSF, 4201 Wilson Blvd., Suite 1045, Arlington VA
22203, fax 703-292-9034, email esm@nsf.gov. Licensees shall notify the International
Bureau once they have completed coordination. Upon receipt of the coordination
agreement from a licensee, the International Bureau will issue a public notice stating that
the licensee may commence operations within the coordination zone in 30 days if no
party has opposed the operations.

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(2) Table 1 provides a list of each applicable RAS site, its location, and the
applicable coordination zone.

Table 1 Applicable Radio Astronomy Service (RAS) Facilities and Associated
Coordination Distances.

Radius (km) of
Observatory Latitude (North) Longitude (West) Coordination Zone
Arecibo
Island of Puerto
Observatory, 18° 20' 37" 66° 45' 11"
Rico
Arecibo PR
Green Bank WV 38° 25' 59" 79° 50' 23" 160
Very Large Array,
34° 04' 44" 107° 37' 06" 160
near Socorro NM
Pisgah
Astronomical
35° 11' 59" 82° 52' 19" 160
Research Institute,
Rosman NC
U of Michigan
Radio Astronomy
Observatory, 42° 23' 56" 83° 56' 11" 160
Stinchfield Woods
MI
Very Long Baseline Array (VLBA) stations:
Owens Valley CA 37° 13' 54" 118° 16' 37" 160*
Mauna Kea HI 19° 48' 05" 155° 27' 20"
Brewster WA 48° 07' 52" 119° 41' 00"
Kitt Peak AZ 31° 57' 23" 111° 36' 45"
Pie Town NM 34° 18' 04" 108° 07' 09"
Los Alamos NM 35° 46' 30" 106° 14' 44" 50
Fort Davis TX 30° 38' 06" 103° 56' 41"
North Liberty IA 41° 46' 17" 91° 34' 27"
Hancock NH 42° 56' 01" 71° 59' 12"
St. Croix VI 17° 45' 24" 64° 35' 01"
* Owens Valley CA operates both a VLBA station and single-dish telescopes.”

The proposed VMES terminals will utilize the same functionality described in paragraph
4.1 above to protect the applicable Radio Astronomy Service facilities listed in § 25.226
Table 1. The VMES Monitor & Control system will compare the GPS-derived location
information with each of the zones calculated from Table 1 and utilize the same
transmitter mute functionality. Additionally, when the Commission specifies that
protection will be provided to future RAS sites, the location of those sites will
additionally be programmed into the VMES Monitor & Control system for similar
comparison.

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The VMES Monitor & Control system is designed to mute the transmitter if the terminal
is determined to be within any of the RAS coordination zones. A special password-
protected feature, only available to VMES system administrators and not available to
normal VMES terminal operators, is provided to override the geographic coordination
zone transmitter mute function for those cases where the required coordination has
successfully been accomplished. Proper operation of this transmitter mute functionality
can be ensured through both local reporting to the VMES operator via the Monitor &
Control system as well as via the remote location logging which is reported to the VMES
network control facility and continuously logged there.

4.3 § 25.226 (e) Global Positioning Satellite position location technology

From § 25.226 (e), “VMES licensees shall use Global Positioning Satellite-related or
other similar position location technology to ensure compliance with paragraphs (c) and
(d) of this section.”

The proposed VMES terminals utilize a GPS receiver to determine the location of the
VMES terminal and, thus, ensure compliance with paragraphs § 25.226 (c) and § 25.226
(d).

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Document Created: 2019-04-18 11:29:10
Document Modified: 2019-04-18 11:29:10

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