White Paper
BLOS Communications
Capability for UAS
An Unmanned Aerial Systems User Guide to Beyond Line-of-Sight Connectivity
STEPHEN J. GIZINSKI III, PRESIDENT, INMARSAT GOVERNMENT
JEFFREY R. GALLOWAY, CHIEF ENGINEER, INMARSAT GOVERNMENT
ALEX H. HAYES, SR. DIRECTOR, PRODUCT DEVELOPMENT AND ENGINEERING, INMARSAT GOVERNMENT
INTRODUCTION
Military operations rely on
Unmanned Aerial Systems
(UAS) for a range of Command
and Control (C2) and
Intelligence, Surveillance and
Reconnaissance (ISR) missions.
Many of these missions
require Beyond Line of Sight
(BLOS) communications links
which can be implemented
using a range of satellite
communications (SATCOM)
architectures. The range
of sizes and capabilities of
UAS, the available satellite
frequency bands, and the
implemented communications
architectures continue to
expand. Just as users must
choose the appropriate UAS for
a given mission, BLOS options
must be carefully considered
as well. This paper provides
a high-level overview of
aeronautical terminal types
that meet low Size, Weight and
Power (SWaP) requirements
and reliable high-throughput
connectivity that might be
implemented in support of UAS
mission data connections. The
goal of this paper is to provide
a helpful, high-level guide
that correlates anticipated
performance based on
terminal SWaP. This will help
UAS users understand BLOS
connectivity options for a
specific platform of interest.
Though, not the primary focus
of this paper, it is important
to note that Inmarsat’s ELERA
L-band and Global Xpress
Ka-band worldwide satellite
enterprise is well suited to
support the governments
expeditionary ISR requirements
today with no or little satellite
bandwidth coordination in the
area of operation required.
We accomplish this through
a variety of wordwide service
offerings across our L-band and
Ka-band networks.
Inmarsat has focused on BLOS
connectivity for worldwide
mobile maritime users since
1979. These connectivity
services initially focused on
safety of life services that
operate in L-band and require
very high availability. As time
has passed and Inmarsat
capabilities have evolved,
services have expanded and
extended to include mobile
high-throughput Ka-band
connectivity services. System
design has been guided
by user requirements and
technical possibilities, with
the primary objectives of
delivering worldwide coverage,
wideband connectivity, and
interoperability with military
Ka-band and applications for
on-the-move users to very high
service standards. Just as in
terrestrial mobile systems, this
requires delivering managed
end-to-end networks, where
satellite connectivity is only
one element of a complete
mobility solution that supports
higher level applications on
a worldwide basis to include
a diverse array of terminals,
advanced modems and
waveforms – including support
for land, sea and air users.
Inmarsat’s mobile worldwide
connectivity services now
provide a wide array of
capabilities ranging from
low-speed Internet of Things
(IoT) messaging services
through very high-speed
services in L-band and Kaband. This paper provides a
high-level view of how these
Inmarsat services might be
used to provide connectivity
to various UAS Groups (Group
2-5 UAS) and missions. This
paper serves as a helpful, factbased input for trade options
associated with selecting a
compatible BLOS aeronautical
terminal solution for a specific
UAS mission. Smaller UAS with
challenging SWaP constraints
are considered (Group 2
UAS). The ability of large UAS
that support larger aperture
aeronautical terminals and
extremely high data rates are
assessed (Group 3, 4 and 5
UAS). These assessments are
all performed using Inmarsat
L-band and Ka-band services
on satellites that are on-orbit
today and available worldwide
(the GEO-visible earth).
INMARSAT
L-BAND SERVICES
Inmarsat’s ELERA advanced
worldwide L-band services are
provided by four GEO satellites
that are on orbit today. An
overview of these satellites
and their areas of coverage
is shown in Exhibit 1. These
include three Inmarsat-4
satellites (I-4 F1-3) and
Alphasat (F4). F1 and F2 were
launched in 2005, and F3 was
launched in 2008 resulting
in the world’s first global 3G
satellite network. Alphasat,
the last satellite in this series
was launched in 2013. The
I4 F1-3 satellites operate in
standard L-band (1525-1559
MHz RX and 1626.5 - 1660.5
MHz TX) and Alphasat F4
operates in standard and
extended L-band (1518-1559
MHz RX and 1626.5 – 1660.5
& 1668.0 – 1675.0 MHz TX).
A variety of services are
supported by these satellites
Uniquely for Inmarsat, the
including the SwiftBroadband
sixth-generation fleet will
(SB) service for aviation users.
feature a dual payload with
UAS platforms leverage
each new I-6 satellite also
Inmarsat L-band services for
supporting L-band and mil and
Command and Control (C2)
commercial Ka-band. I-6 F1 is
capability. Scalable data plans
ensure flexible coverage and OURscheduled for launch at the
end of 2021 with the second,
capacity for ever changing
I-6 F2 to follow in 2022.
missions. Service plans
start with pay-as-you-go (or
subscriptions) and scale up to
leases of spectrum, or leases
I-4
managed by our “SATCOM
as a Service” offerings. For
specialty missions that require
rapid deployment and high
flexibility, we offer Quick
Reaction Capability (QRC) – a
premium L-band service that
allows for globally portable,
rapid stand-up or relocating
leases. Next generation L-band
services will be delivered by
the Inmarsat-6 (I-6) series
of satellites, which consist
of two satellites (F1 and F2). INMARSAT.COM
COVerage
Exhibit 1: L-band coverage map. The Inmarsat’s ELERA satellites provide worldwide L-band coverage.
These satellites support subscriptions services (e.g., SwiftBroadband) and lease services (e.g., LAISR)
anywhere in the area of coverage.
Combined I-4 coverage
I-4 F1
I-4 F2
I-4 F3
I-4 F4
90°
80°
70°
60°
50°
40°
30°
20°
10°
0°
10°
20°
30°
40°
50°
60°
70°
80°
90°
180°
160°
140°
120°
100°
80°
60°
40°
20°
0°
20°
40°
60°
80°
100°
120°
140°
160°
180°
This map is for general information purposes only and no guarantee is given of accuracy or fitness for a particular use. Coverage is subject to change at any time. I-4 coverage May 2020.
INMARSAT
KA-BAND SERVICES
Exhibit 2: GX1-5 coverage map. GX1-5 satellites provide worldwide commercial Ka-band coverage and
steerable spot beam military Ka-band coverage. These satellites support subscription services (e.g.,
GX SATCOM as a Service) or steerable beam Mil Ka-band services anywhere in the area of coverage.
GX1 -10B
Not Covered
90°
OUR
COVerage
GLOBAL XPRESS
GX1 - 10B 2024 anticipated coverage
80°
70°
60°
50°
40°
30°
20°
GX commercial service (SATCOM as a Service)
GX steerable beams (Mil-Ka)
10°
0°
10°
Inmarsat Ka-band services,
Global Xpress (GX), are provided
via five satellites, GX1-5, that
are on-orbit today and provide
commercial and military Kaband capability worldwide. An
overview of these satellites
and their areas of coverage
is shown in Exhibit 2. The first
three GX satellites, GX1-3 were
launched between 2013-2015,
with global commercial service
started in December 2015. GX4
was launched in May 2017 to
provide additional capacity.
GX5, a Very High Throughput
Satellite (V-HTS), delivers
more capacity than the entire
GX1-GX4 fleet combined and
has been in commercial service
since December 2020 to
meet growing demand across
Europe and the Middle East.
The GX1-5 network provides
a subscription service for
commercial Ka-band terminals.
These satellites also provide
high-capacity steerable beams
that are used to seamlessly
complement military satellite
communication (MILSATCOM)
systems like the Wideband
Global SATCOM system (WGS)
and to provide very highperformance Military (Mil)
Ka-band connectivity. The GX
services operate in the 29-30
GHz TX and 19.2-20.2 GHz RX
band providing worldwide
coverage. Mil Ka-band services
(accommodated on the high
capacity steerables) operate
in the 30-31 GHz TX and 20.221.2 GHz RX band providing
1.2° steerable spot beam
antennas with 40 to 730 MHz
of transponder bandwidth.
Next-generation GX and Mil
Ka-band services will be
delivered by the I-6 series
of hybrid satellites. The two
Ka-band payloads, GX6A and
GX6B, will provide additional
GX capacity, two Mil Ka-band
steerables per satellite and
a unique dedicated gateway
link. The next evolution of
GX includes GX extension to
Arctic via the GX10A and GX10B
payloadsINMARSAT.COM
in HEO to provide
continuous coverage above
65N in commercial and Mil Kaband, scheduled for launch in
2022. The GX7, 8 & 9 satellites
which will provide dynamic
beamforming, allowing for
the simultaneous
creation of
OUR
thousands of independent
beams in commercial and
Mil Ka-band that can be
GLOBALand
XPRESS
reconfigured
repositioned
GX1 - 10B 2024 anticipated coverage
across the globe in real time,
GX commercial service (SATCOM as a Service)
due to beGXlaunched
steerable beamsfrom
(Mil-Ka) 2023.
COVerage
20°
30°
40°
50°
60°
70°
80°
90°
180°
160°
140°
120°
Global Xpress network available
over at least 99% of this area
Global Xpress network available
over at least 99% of this area
100°
80°
60°
40°
20°
0°
20°
40°
60°
80°
100°
120°
140°
160°
180°
Extendable Global Xpress
GX1
GX2
GX3
GX4
GX5 steerable
GX5 commercial service area
coverage
via issteerable
beams purposes only and no guarantee is given of accuracy or fitness for a particular use. Coverage is subject
This map
for general information
to change
Global Xpress
Coverage. March 2021
beam
area at any time. Government
(SATCOM
as aGX1-10B
service)
Extendable Global Xpress
GX1
GX2
GX3
GX4
GX5 steerable
GX5 commercial service area
coverage via steerable beams
beam area
(SATCOM as a service)
Exhibit 3: GX1-10B anticipated coverage map. GX1-10B provides worldwide coverage and includes
GX commercial service (SATCOM as a Service) and Mil Ka steerable breams.
GX1 -10B
Not Covered
90°
80°
70°
60°
50°
40°
30°
20°
10°
0°
10°
20°
30°
40°
50°
60°
70°
80°
INMARSAT.COM
90°
180°
160°
140°
120°
100°
80°
60°
40°
20°
0°
20°
40°
60°
80°
100°
120°
140°
160°
180°
This map is for general information purposes only and no guarantee is given of accuracy or fitness for a particular use. Coverage is subject to change at any time. Government Global Xpress GX1-10B Coverage. March 2021
UAS GROUPS
For the purposes of this paper,
we make use of the United
States Department of Defense
(DoD) Classification for UAS
Groups shown Exhibit 4. This
paper assesses connectivity
options and applicable
aeronautical terminals for
Groups 2-5 UAS. The sections
below provide an overview
of the general aeronautical
terminal characteristics
for the various UAS groups.
Information includes antenna
size, power amplifier size,
plausible frequency bands
of operations and expected
forward (to the UAS) and
return (from the UAS) link
performance. This summary
is not intended to be an
exhaustive treatment. Instead,
it allows the reader to gain
a general sense of plausible
aeronautical terminals that
may be employed for BLOS
communications and the
supported data rates.
GROUP 2 UAS TERMINALS
Group 2 UAS are characterized
by very constrained
aeronautical terminal
accommodations. The limited
accommodations force a range
of compromises among key
attributes (SWaP, forward link
data rate, return link data rate).
Typically, these terminals have
very small antennas which
impact the available transmit
and receive gain making the
link budget more challenging.
Further, these small antennas
yield a wide beamwidth
making compliance with offaxis emissions requirements
(regulatory) more difficult
while also making the terminal
more susceptible to adjacent
satellite interference. Antennas
for Group 2 UAS typically range
from 5 cm to 20 cm in diameter.
Antennas for these UAS are
usually parabolic or flat panel in
shape, and the overall terminal
is designed to be as lightweight
as possible. Limited available
platform power restricts RF
power amplifiers to the range
of 5 W to 16 W which effectively
limits the Effective Isotropic
Radiated Power (EIRP). Lower
terminal EIRP yields lower
return link (UAS to gateway)
data rates. Operations for
these UAS generally occur
at low altitude (under the
weather) which requires
careful consideration of band
selection and management
of link margins. Ideal band
of operation for Group 2 UAS
terminals when using Inmarsat
resources is L-band. With the
right terminal and link design,
it is possible to use Mil Ka-band
to support connectivity.
GROUP 3 UAS TERMINALS
Group 3 UAS provide ample
aeronautical terminal
accommodations. Aeronautical
terminal antennas for Group
3 UAS typically range in
size from 20 cm to 46 cm in
diameter. Terminals are usually
parabolic or flat panel in shape.
Available platform power
supports RF power amplifiers
in the range of 16 W to 50 W.
Operations generally occur
at medium to high altitude
for these platforms. The ideal
frequency band of operation for
Group 3 aeronautical terminals
is commercial or Mil Ka-band.
For special circumstances, it
is possible to use L-band lease
services for these terminals too.
diameter parabolic apertures),
significant available platform
power to support operations
(utilizing 50 W to 250 W
RF power amplifiers), and
operations at high altitude
(above most weather effects).
Ideal band of operation for these
terminals when using Inmarsat
resources is commercial or
military Ka-band.
GROUP 4 AND GROUP 5
UAS TERMINALS
Group 4 and Group 5 UAS
provide the most significant
aeronautical terminal
accommodations of all the
UAS categories. Aeronautical
terminals for these UAS are
characterized by very large
antennas (46 cm to 1.2 m
Exhibit 4: DoD UAS classification. United States Department of Defense (DoD) classification for UAS groups.
SIZE
MAXIMUM GROSS
TAKEOFF WEIGHT
(MGTW) (LBS)
NORMAL
OPERATING
ALTITUDE (FT)
AIRSPEED
(KNOTS)
Group 1
Small
0-20
<1,200 AGL*
<100
CATEGORY
Group 2
Medium
21-55
<3,500
<250
Group 3
Large
<1320
<18,000 MSL**
<250
Group 4
Larger
>1320
<18,000 MSL
Any airspeed
Group 5
Largest
>1320
>18,000
Any airspeed
*AGL = Above Ground Level
**MSL = Mean Sea Level
Note: If the UAS has even one characteristic of the next level, it is classified in that level.
Source: “Eyes of the Army” U.S. Army Roadmap for UAS 2010-2035
UAS BLOS TERMINALS
SAMPLE L-BAND TERMINALS
TERMINALS LINK PERFORMANCE
COBHAM AVIATOR UAS 200
The sections that follow
describe a series of sample
terminals that operate in L-band
and Ka-band and summarize
expected link performance
(supported data rates). In
L-band, the SwiftBroadband
family of terminals support
subscription services at modest
rates, while the LAISR terminal
variants offer the highest data
rate subscriptions in support of
high throughput ISR payloads
such as full-motion video (FMV).
The data rates supported by the
prospective L-band terminals
are provided in the descriptions
below. In Ka-band, the terminals
discussed provide on-demand
support for subscription
services in commercial Ka-band
and lease-based services in
Mil Ka-band. The data rates
supported by the prospective
Ka-band terminals are provided
in the sections that follow.
The Aviator UAS 200 is
a recently developed
aeronautical terminal solution
that has been purpose built to
meet UAS BLOS connectivity
needs. This aeronautical
terminal is comprised of a
single, lightweight LRU. The
Aviator UAS 200 operates
across a wide temperature
range (-40°C to +55°C) and
at altitudes up to 6,000 m.
Connectivity for this terminal
is provided via Inmarsat’s
SwiftBroadband service. A
single, purchased subscription
provides worldwide access.
A summary of the key
characteristics of the UAS 200
terminal is shown in Exhibit 5.
Exhibit 5: Cobham Aviator UAS 200
COBHAM AVIATOR UAS-200
Antenna Mounting
Inside Aircraft Fuselage
Input Power
28 VDC
No. Components
1
Total Weight
3.2 lbs.
Dimensions (inches)
9.5 x 6.3 x 2.4
Total Size (Volume)
108 cu. Inch
Max Power Draw (@28 VDC)
28 W
User Data Interface
Ethernet
NAV Interface
RS-232 or Ethernet
Support Data Rates
Class 4 SwiftBroadband to 5
deg elevation;
Background IP to 200 kbps;
Streaming to 32 kbps with
Half HDR
COBHAM AVIATORSP
The Cobham AviatorSP provides robust connectivity using Inmarsat’s SwiftBroadband service. In a
single channel configuration, the terminal consists of three LRUs as shown in Exhibit 6. The single
channel terminal has been ruggedized to meet the demanding needs of the aircraft and helicopter
environment and reliably supports duplex data rates of up to 432 kbps depending on the selected
antenna. The AviatorSP Multi Channel System provides robust multi-channel connectivity using
Inmarsat’s SwiftBroadband service. The terminal is offered in two- and four-channel versions and is
comprised of 4 LRUs. Exhibit 7 summarizes the key characteristics of the two-channel system; Exhibit 8
summarizes the key characteristics of the four-channel system. The only hardware difference between
the two systems is the four-channel uses a slightly larger (ARINC-600 3 MCU form factor) SDU.
Exhibit 6: Cobham AviatorSP Single Channel
ANTENNA CLASS
CLASS 15
CLASS 7
CLASS 6
Omni
Electronic
Phased-Array
Mechanical
Helix
Electronic
Phased-Array
Antenna Mounting
Fuselage Blade
Fuselage Mount
Tail Mount
Fuselage Mount
No. Components
Three individual pieces: Satellite Data Unit (SDU), HPA/DLNA (HLD), Antenna
Antenna Type
LRU Dimensions
(L x W x H inches)
Antenna
Dimensions
(L x W x H inches)
Total Weight
Total Size (Volume)
13.6 x 3.4 x 4.4
22.9 x 6.9 x 2.0
10.0 x 9.7 x 10.0
41.4 x 11.8 x 2.0
13.3 lbs.
19.6 lbs.
15.9 lbs.
32.9 lbs.
436 cu. Inch
412 cu. Inch
1180 cu. Inch
1182 cu. Inch
Input Power
Max Power Draw
HLD
7.8 x 7.5 x 2.4
SDU
13.1 x 7.6 x 2.0
20.5 - 32.2 VDC, normal +28 VDC
89 W @ 28 VDC
Data Interface
96 W @ 28 VDC
111 W @ 28 VDC
109 W @ 28 VDC
Ethernet
NAV Interface
Not Required
Background IP
Data Rates
Up to 200 kbps
Up to 332 kbps
Up to 432 kbps
Streaming IP
Data Rates
8, 16, or 32 kbps
8, 16, 32, 64, or
128 kbps
8, 16, 32, 64, or 128 kbps or
X-stream (up to 256 kbps)
ARINC-429
COBHAM AVIATORSP — TWO-CHANNEL
The key characteristics of the Cobham AviatorSP Two-Channel terminal are shown in Exhibit 7.
The terminal is offered in two variants – a Class 7 version, and Class 6 version. Both variants use
the same Class 6 and 7 antennas as used in the single-channel system; the differences are the
two-channel systems uses a stand-alone HPA and DLNA, and an ARINC-600 two MCU form factor
SDU. The terminal provides up to two channels of SwiftBroadband at the same per channel data
rates as the single-channel system. The Class 6 variant can bond up to two channels to provide an
aggregate throughput of 800 kbps.
Exhibit 7: Cobham Aviator-SP Two-Channel
ANTENNA CLASS
Antenna Type
Antenna Mounting
No. Components
LRU Dimensions
(L x W x H inches)
Antenna
Dimensions
(L x W x H inches)
Total Weight
Total Size (Volume)
CLASS 7
CLASS 6
Electronic Phased-Array
Mechanical Helix
Electronic Phased-Array
Fuselage Blade
Tail Mount
Fuselage Mount
Four individual pieces: Satellite Data Unit (SDU), HPA-7450, DLNA, Antenna
SDU
12.6 x 2.4 x 7.6
(ARINC-600 2 MCU)
DLNA
11.2 x 7.8 x 2.0
HPA
13.5 x 2.4 x 7.6
(ARINC-600 2 MCU)
22.9 x 6.9 x 2.0
10.0 x 9.7 x 10.0
41.4 x 11.8 x 2.0
30.9 lbs.
27.2 lbs.
44.2 lbs.
636 cu. Inch
1404 cu. Inch
1406 cu. Inch
Input Power
Max Power Draw
20.5 - 32.2 VDC, normal +28 VDC
277 W @ 28 VDC
293 W @ 28 VDC
Data Interface
Ethernet
NAV Interface
ARINC-429
Background IP
Data Rates
Streaming IP
Data Rates
290 W @ 28 VDC
Up to 332 kbps
(per channel)
Up to 432 kbps
(per channel)
8, 16, 32, 64, or 128 kbps
(per channel)
8, 16, 32, 64, or 128 kbps or X-stream (up to 256
kbps) per channel; bonded service up to 800 kbps
COBHAM AVIATORSP — FOUR-CHANNEL
The key characteristics of the Cobham AviatorSP Four-Channel terminal are shown in Exhibit 8
below. The terminal provides up to four channels of SwiftBroadband at the same per channel data
rates as the single-channel system. The terminal uses the same antennas and RF electronics as
with the two-channel system; the only difference is that the four-channel system uses a larger
ARINC-600 form factor SDU (three MCUs). The Class 6 variant can bond up to four channels to
provide an aggregate throughput of 1600 kbps.
Exhibit 8: Cobham Aviator-SP Four-Channel
ANTENNA CLASS
Antenna Type
Antenna Mounting
No. Components
LRU Dimensions
(L x W x H inches)
Antenna
Dimensions
(L x W x H inches)
Total Weight
Total Size (Volume)
CLASS 7
CLASS 6
Electronic Phased-Array
Mechanical Helix
Electronic Phased-Array
Fuselage Blade
Tail Mount
Fuselage Mount
Four individual pieces: Satellite Data Unit (SDU), HPA-7450, DLNA, Antenna
SDU
13.5 x 3.7 x 7.6
(ARINC-600 2 MCU)
DLNA
11.2 x 7.8 x 2.0
HPA
13.5 x 2.4 x 7.6
(ARINC-600 2 MCU)
22.9 x 6.9 x 2.0
10.0 x 9.7 x 10.0
41.4 x 11.8 x 2.0
32.7 lbs.
29 lbs.
46 lbs.
741 cu. Inch
1509 cu. Inch
1511 cu. Inch
Input Power
Max Power Draw
20.5 - 32.2 VDC, normal +28 VDC
297 W @ 28 VDC
313 W @ 28 VDC
Data Interface
Ethernet
NAV Interface
ARINC-429
Background IP
Data Rates
Streaming IP
Data Rates
310 W @ 28 VDC
Up to 332 kbps
(per channel)
Up to 432 kbps
(per channel)
8, 16, 32, 64, or 128 kbps
(per channel)
8, 16, 32, 64, or 128 kbps or X-stream (up to 256
kbps) per channel; bonded service up to 800 kbps
HONEYWELL ASPIRE 200
The key characteristics of the Honeywell Aspire 200 terminal are shown in Exhibit 9. The terminal
is offered in two variants – a Class 7 version, and Class 6 version. The terminal provides data rates up
to 332 kbps (Class 7) or 432 kbps (Class 6). In addition, the terminal can support Inmarsat High-Data
Rate (HDR) service. In this configuration, the Class 7 terminal can support data rates up to 500 kbps
streaming and the Class 6 systems can support up to 650 kbps streaming. The Aspire 200 terminal
serves UAS Group 3+.
Exhibit 9: Honeywell Aspire 200
ANTENNA CLASS
Antenna Type
Antenna Mounting
No. Components
CLASS 7
CLASS 6
Electronic Phased-Array
Mechanical Helix
Electronic Phased-Array
Fuselage Blade
Tail Mount
Fuselage Mount
Three individual pieces: Satellite Data Unit (SDU), HPA/DLNA (HLD), Antenna
LRU Dimensions (L
x W x H inches)
IPLD
7.5 x 7.5 x 2.5
HDU
14.8 x 2.4 x 7.8
Antenna
Dimensions
(L x W x H inches)
Total Weight
Total Size (Volume)
18.3 x 7.6 x 2.0
10.0 x 10.0 x 9.7
43.0 x 14.3 x 2.5
21.0 lbs.
18.9 lbs.
34.4 lbs.
420 cu. Inch
1194 cu. Inch
1498 cu. Inch
Input Power
Max Power Draw
20.5 - 32.2 VDC, normal +28 VDC
100 W @ 28 VDC
110 W @ 28 VDC
Data Interface
Ethernet
NAV Interface
ARINC-429
Background IP
Data Rates
Streaming IP
Data Rates
115 W @ 28 VDC
Up to 332 kbps
Up to 432 kbps
8, 16, 32, 64, or 128 kbps;
up to 500 kbps with HDR
8, 16, 32, 64, or 128 kbps or X-stream (up to 256
kbps) per channel; up to 600 kbps with HDR
LAISR
LAISR (L-band Airborne Intelligence, Surveillance, and Reconnaissance) is an L-band subscription
service that provides speeds of 3 Mbps using low SWaP terminals. It supports high-throughput
Airborne ISR payloads throughout the complete coverage area of Inmarsat’s ELERA network. All
traffic passes through Inmarsat Satellite Access Stations (SAS) and is backhauled via Inmarsat
Government’s secure Multiprotocol Label Switching (MPLS) network to the customer’s specific
destination – ground control stations, operation centers or remote terminals anywhere worldwide
– via private terrestrial line connections, the public Internet or SATCOM. It can be configured to
meet the unique requirements of government customers, and is managed 24/7 by U.S.-based,
security-cleared operations and engineering teams.
Exhibit 10: Overview of LAISR-LW terminals
Terminal
LAISR-ULW
SE*
LAISR-LW
3010
LAISR-LW
3035
LAISR-ULW
3035
LAISR-LW
3040
LAISR-LW
3050
Dimensions
(Antenna)
11.7“ x 8.1“
x 2.0“
5.0“ x 5.0“
x 1.0“
10.0" x 12.0"
x 2.0"
10.0" x 12.0"
x 2.0"
10.0“ x 10.0“
x 9.7“
18.3” x 7.6”
x 2.0”
We guarantee the LAISR service integration end-to-end. Our ecosystem of in-house and partner teams of
experienced UAS SATCOM engineers work to identify the hardware options and network configurations to
meet specific SWaP, mission and budget requirements.
Total System
Weight
(Terminal)
3.0 lbs.
8.6 lbs.
9.4 lbs.
5 lbs.
12.2 lbs.
12.9 lbs.
The LAISR service is offered via flexible service plans that allow multiple user terminals to share a lease
and provides globally portable leases that can be rapidly activated or relocated to enable operations.
Data Rate
~2 Mbps**
~2 Mbps**
~2.5 Mbps**
~3 Mbps**
~3 Mbps**
~3 Mbps**
13 VDC,
60 W
28 VDC,
115 W
28 VDC,
125 W
28 VDC,
TBD W
28 VDC,
140 W
28 VDC,
140 W
2+
3+
3+
2+
3+
3+
Ƈ Standard Lease Service providesdedicated leased spectrum in one or more narrow spot beams
on Inmarsat’s ELERA wordwide network. Spectrum automatically switches between beams to
follow user terminal via the Network Management System (NMS). This service enables seamless
communications over large geographic areas.
Ƈ Shared Forward Lease Service (point to multipoint) enables forward channel bandwidth to be
shared by all active user terminals. It eliminates the need to have individual, dedicated forward
channels per terminal, while still supporting simultaneous operations. This service is ideal for
UAS with minimal forward channel bandwidth requirements.
Ƈ Quick Reaction Capability (QRC) is a premium service option that offers globally portable leases
that can be rapidly stood-up or relocated to enable operations. The service delivers speeds of 3
Mbps and comes with 24/7 support by Inmarsat Government’s U.S.-based Network Operations
Center (NOC), which serves as a customer’s single point of contact for initiating QRC call-up requests
and coordinating service transfers. On-call engineering support is also available. Reserved QRC hub
modems are installed at all Inmarsat SASs.
LAISR is accessible via Inmarsat type approved low-profile, small form-factor LAISR-Lightweight
(LW) terminals that maximize UAS platform range and reduce signatures. LAISR-LW provides
several antenna models with slightly different configurations that correspond to unique user
requirements, as shown in Exhibit 10.
These terminals feature very compact size and low weight thus enabling extended loiter time and
use of the LAISR service on smaller platforms. Some variations of this terminal will feature fullduplex DVBS2X links, thus allowing higher data rates to the UAS.
Power
UAS Group
* Terminal is a single LRU consisting of the antenna and integrated core module.
** Data rates may vary and depend upon terminal type, bandwidth leased, operating location, etc.
SAMPLE KA-BAND TERMINALS
A wide range of parabolic, flat-panel and electronically-steerable antennas (ESA) has been developed and type-approved to operate
on the GX network. Additional terminals are in the development process to meet various user requirements. Exhibit 11 provides the
specifications for typical terminals. The data rates are estimates based on factors such as using a modem with available symbol rates
up to 80 Mbps and modulation and coding (MODCOD) rates of up to 64APSK-5/6, operating in clear sky conditions, using up to
100 MHz of transponder bandwidth and/or power, and configuring transponder settings for optimum performance.
Exhibit 11: Overview of Ka-band terminals
r
Unde ent
lopm
Deve
Terminal
Get SAT MilliSAT H LW
Get SAT MilliSAT W LW
Get SAT MilliSAT EX
Orbit GX30
OrbitGX46
OrbitGX76
Ball Ka 1204A
10.6” x 9.8”
Flat Panel
5.3” x 19.7”
Flat Panel
7.9” x 18.8”
Flat Panel
12”
Parabolic
18”
Parabolic
30”
Parabolic
20.9” x 56” x 2.8”
ESA
Terminal Weight*
39.2 lbs.
41.0 lbs.
45.7 lbs.
44.0 lbs.
47.6 lbs.
TBD
112.8 lbs.
Comm Data Rate
Mil Ka Data Rate
(Typical)
6x2 Mbps
50x15 Mbps
6x2 Mbps
50x15 Mbps
6x2 Mbps
55x13 Mbps
6x2 Mbps
50x13 Mbps
10x6 Mbps
65x18 Mbps
12x8 Mbps
80x40 Mbps
8x4 Mbps
80x20 Mbps
Comm Data Rate
Mil Ka Data Rate
(Most Favorable)
70x7 Mbps
115x39 Mbps
70x9 Mbps
115x39 Mbps
70x9 Mbps
115x32 Mbps
70x11 Mbps
145x38 Mbps
80x25 Mbps
174x92 Mbps
89x34 Mbps
200x150Mbps
80x20 Mbps
175x150Mbps
28 VDC, 265 W
28 VDC, 265 W
28 VDC, 215 W
28 VDC. 395 W
28 VDC, 395 W
TBD
28 VDC, 3100 W
Commercial / Military
Commercial / Military
Commercial / Military
Commercial / Military
Commercial / Military
Commercial / Military
Commercial / Military
3+
3+
3+
3+
3 / 4+
4+
4+
Terminal Size
Antenna Type
Power
Ka-band
UAS Group
* Weight doesn’t include required cabling.
GET SAT MILLISAT H LW
Exhibit 12: MilliSAT H LW terminal performance using GX commercial Ka-band subscription services.
The Get SAT MilliSAT H LW is a lightweight, portable on-the-move SATCOM terminal solution. It is optimal
for airborne connectivity, compact installations and fully autonomous operation. The design has
emphasized efficient terminal SWaP characteristics. The terminal supports commercial and Mil
Ka-band and includes an embedded SCPC modem to support transmit and receive operations on Mil
Ka-band. More details regarding this terminal are shown in Exhibit 11.
As shown in Exhibit 12, using the commercial Ka-band subscription services, the Get SAT MilliSAT H LW
terminal provides a typical forward link up to 6 Mbps and a return link up to 2 Mbps with Committed
Information Rages (CIR) throughout the world and backed by Service Level Agreements (SLA). The
terminal’s most favorable forward link can reach up to 70 Mbps and a return link up to 7 Mbps.
It is possible to operate the Get SAT MilliSAT H LW terminal on an Inmarsat Mil Ka-band steerable
beam with a typical forward link up to 50 Mbps and a return link up to 15 Mbps, as shown in Exhibit
13. A most favorable forward link can achieve up to 115 Mbps and a return link up to 39 Mbps. More
details regarding this terminal are shown in Exhibit 11.
Exhibit 13 provides an overview of the forward and return link performance for this antenna using
the High Capacity Cross-strapped (HCX) configuration (Mil Ka-band user link with commercial Kaband feeder link). HCX provides a 100 MHz duplex transponder. Performance analysis is based on
clear sky or above-the-clouds conditions and the use of a high-performance modem.
Exhibit 13: MilliSAT H LW performance using Inmarsat Mil Ka-band HCX.
GET SAT MILLISAT W LW
Exhibit 14: Get SAT MilliSAT W LW terminal performance using commercial Ka-band subscription services.
Get SAT MilliSAT W LW is a lightweight portable on-the-move satellite terminal solution. It is optimal
for airborne connectivity, for compact installations and for fully autonomous operation. With its
unique all-in-one design, the MilliSAT W LW is suited for UAS platforms Group 3 and up. Its optimized
form, size and weight enable it to be deployed as an integral part of the plane. It is designed for
applications that require higher bandwidth and can accommodate the enabling increase in form
factor. MilliSAT W LW is optimized for larger bandwidth requirements with a minimal footprint.
As shown in Exhibit 14, using the commercial Ka-band subscription services, the MilliSAT W LW terminal
provides a typical forward link up to 6 Mbps and a return link up to 2 Mbps, with CIR throughout the
world and backed by SLA. A most favorable forward link can achieve up to 70 Mbps and a return link
up to 9 Mbps.
It is possible to operate this MilliSAT W LW terminal on an Inmarsat Mil Ka-band steerable beam with
a typical forward link up to 50 Mbps and return link up to 15 Mbps, as shown in Exhbit 15. A most
favorable forward link can achieve up to 115 Mbps and a return link up to 39 Mbps. More details
regarding this terminal are shown in Exhibit 11.
Exhibit 15: Get SAT MilliSAT W LW antenna performance using Inmarsat Mil Ka-band HCX.
GET SAT MILLISAT EX
Exhibit 16: Get SAT MilliSAT EX performance using commercial Ka-band subscription services.
Get SAT Milli SAT-EX airborne terminal is a compact all-in-one, on-the-move Ka-band solution that is
fully interoperable with military Ka-band systems and optimized for use over the GX constellation in
commercial and Mil Ka-band. This lightweight satellite terminal solution is tailored to meet missioncritical roll-on/roll-off requirements of C-130 airborne applications without requiring any modification
to the aircraft.
Leveraging Get SAT’s highly efficient, patented InterFLAT miniaturized flat panel antenna technologies,
integrated with R4’s MPHS, the solution reduces weight by 50 percent from previous hatch mount
solutions. This alleviates design and operational concerns of large radomes.
The Milli SAT-EX 7.9”x18.9” flat panel antenna fits inside a 12.5” radome allowing easy installation.
With industry leading SWaP, the unit is an important new addition to Inmarsat type-approved small
airborne SATCOM terminals used with GX.
As shown in Exhibit 14, using the commercial Ka-band subscription services, the MilliSAT W LW terminal
provides a typical forward link up to 6 Mbps and a return link up to 2 Mbps, with CIR throughout the
world and backed by SLA. A most favorable forward link can achieve up to 70 Mbps and a return link
up to 9 Mbps.
It is possible to operate the Milli SAT-EX terminal on an Inmarsat Mil Ka-band steerable beam with
a typical forward link up to 55 Mbps and a return link of up to 13 Mbps, as shown in Exhbit 17. A
most favorable forward link can achieve up to 115 Mbps and a return link up to 32 Mbps. More
details regarding this terminal are shown in Exhibit 11.
Exhibit 17: Get SAT MilliSAT EX performance using Inmarsat Mil Ka-band HCX.
ORBIT GX30
Exhibit 18: Orbit GX30 performance using commercial Ka-band subscription services.
The Orbit GX30 is a compact multi-purpose terminal, featuring a 30 cm (12”) parabolic antenna
that operates in the GX commercial and Inmarsat Mil Ka-bands and delivers high-throughput
connecting for UAS platforms Group 3 and higher. Built to fulfill “anytime, anywhere” connectivity
requirements, the lightweight, small-footprint terminal combines high performance with industryleading reliability to address new opportunities in military aircraft and UAS.
As described in Exhibit 18, using the commercial Ka-band subscription services, the GX30 parabolic
antenna provides a typical forward link up to 6 Mbps and a return link up to 2 Mbps, with CIR throughout
the world and backed by SLA. A most favorable forward link can reach up to 70 Mbps and a return link up
to 11 Mbps.
It is possible to operate the GX30 terminal on an Inmarsat Mil Ka-band steerable beam with a
typical forward link up to 50 Mbps and a return link up to 13 Mbps. A most favorable forward link
can achieve up to 145 Mbps and a return link up to 38 Mbps, as shown in Exhibit 19. More details
regarding this terminal are shown in Exhibit 11.
Exhibit 19: Orbit GX30 performance using Inmarsat Mil Ka-band HCX.
ORBIT GX46
Exhibit 20:Orbit GX46 performance using commercial Ka-band subscription services.
Orbit GX46 multi-purpose terminal is a modular, multi-role parabolic terminal that operates in the
GX commercial and Mil Ka-bands through a 46cm (18”) antenna. The terminal is fully integrated with
modem, electronics and software to ensure reliable operations worldwide. The terminal enables a wide
range of communications capabilities for UAS Group 3 and higher. It complies with industry regulations
and standards including Federal Communications Commission (FCC), European Telecommunications
Standards Institute (ETSI), Inmarsat GX, and RTCA DO-160G for the entire spectrum of aircraft.
The lightweight, small-footprint terminal enables worldwide connectivity, supporting the full range
of Ka frequency bands and has been built to be compatible with the Wideband Global SATCOM (WGS)
system. The terminal is electronically switchable between systems and bands via Automatic Beam
Switching (ABS) using industry-standard OpenAMIP and OpenBMIP protocols, ensuring seamless
operations.
As shown in Exhibit 20, using the commercial Ka-band subscription services, the GX46 parabolic
antenna provides a typical forward link up to 10 Mbps and a return link up to 6 Mbps, with CIR
throughout the world and backed by SLA. A most favorable forward link can achieve up to 80 Mbps
and a return link up to 25 Mbps.
It is possible to operate the GX46 terminal on an Inmarsat Mil Ka-band steerable beam with a typical
forward link up to 65 Mbps and a return link up to 18 Mbps. A most favorable forward link can achieve
up to 174 Mbps and a return link up to 92 Mbps, as shown in Exhibit 21. More details regarding this
terminal are shown in Exhibit 11.
Exhibit 21: Orbit GX46 performance using Inmarsat Mil Ka-band HCX.
ORBIT GX76
Exhibit 22: Orbit GX76 notional performance using commercial Ka-band subscription services.
Orbit GX76 terminal is currently in development and will follow the same design and architecture
as the GX30 and GX46 terminals, however, will provide additional capabilities by means of larger
antenna and associated electronics.
It will be built to enable worldwide connectivity, supporting the full range of Ka frequency bands
and will be compatible with military satellite systems. The terminal will be electronically switchable
between systems and bands via Automatic Beam Switching (ABS) using industry-standard OpenAMIP
and OpenBMIP protocols, ensuring seamless operations.
As shown in Exhibit 22, using the commercial Ka-band subscription services, the Orbit GX76 parabolic
antenna is expected to provide a typical forward link up to 12 Mbps and a return link up to 8 Mbps,
with CIR throughout the world and backed by SLA. A most favorable return link is expected to achieve
up to 89 Mbps and a return link up to 34 Mbps.
It will be possible to operate the GX76 terminal on an Inmarsat Mil Ka-band steerable beam with a
typical forward link up to 80 Mbps and a return link up to 40 Mbps. A most favorable forward link
will be able to achieve up to 200 Mbps and a return link up to 150 Mbps, as shown in Exhibit 23. More
details regarding this terminal are shown in Exhibit 11.
Exhibit 23: Orbit GX76 notional performance using Inmarsat Mil Ka-band HCX.
BALL KA 1204A
Ball Ka 1204A is an electronically steerable Ka-band phased array antenna featuring Ball Aerospace’s
innovative subarray architecture. Designed for optimal flexibility and cost efficiency, subarrays can
be tiled together to form an antenna that is customized to meet an end user’s needs. The architecture
allows independent scaling of transmit and receive antenna sizes and supports distributed antenna
solutions. This approach allows the flexibility to optimize a terminal to the needs of the user without
the cost of antenna re-design. Fully electronically steerable (ESA), the Ka 1204A flat antennas has no
moving parts, providing long-term reliability with lower maintenance costs. Their low profile enables
the design of flat terminals to meet a range of UAS use cases.
Exhibit 24:Ball Ka 1204A notional performance using commercial Ka-band subscription services.
Single Crown-Mounted Configuration
Dual Saddlebag Configuration
As shown in Exhibit 24, using the commercial Ka-band subscription services, the Ka 1204A ESA antenna
is expected to provide a typical forward link up to 8 Mbps and a return link up to 4 Mbps, with CIR
throughout the world and backed by SLA. A most favorable forward link is expected to achieve up to
80 Mbps and a return link up to 34 Mbps.
It will be possible to operate the Ka 1204A terminal on an Inmarsat Mil Ka-band steerable beam with
a forward link up to 80 Mbps and a return link up to 20 Mbps, as shown in Exhibit 25; and a most
favorable forward link up to 175 Mbps and a return link up to 150 Mbps. More details regarding this
terminal are shown in Exhibit 11.
Exhibit 25: Ball Ka 1204A notional performance using Inmarsat Mil Ka-band HCX.
USE CASES FOR KA-BAND TERMINALS
The wide range of parabolic, flat-panel and electronically-steerable antenna (ESA) allows for flexibility
in employment for various use cases on various sized UAS platforms. We provide three typical uses
cases for Ka-band terminals.
Ƈ Use Case 1 shows a scenario with a lightweight UAS with moderate data rate requirements to
pass video, low-rate sensor data, and/or to act as a voice radio relay. Typical terminals for this
use case may include the Get SAT MilliSAT H LW, the Get SAT MilliSAT W LW and the Orbit GX30.
Exhibit 26: Use Case 1 for Ka-band terminals
Tactical ISR,
Voice Relay,
Full Motion Video
Ƈ Use Case 2 shows a scenario with a more capable UAS with higher data rate requirements to
pass video and other information from multiple sensors.Typical terminals for this use case may
include the Get SAT MilliSAT EX and the Orbit GX46.
Ƈ Use Case 3 shows a scenario with the most capable UAS with very high data rate requirements.
Typical terminals for this use case may include the Orbit GX46, GX76 and the Ball 1204A.
Global Xpress
SAS
Inmarsat Terrestrial
Infrastructure
DoD Network
Global Xpress
SAS
Inmarsat Terrestrial
Infrastructure
DoD Network
Global Xpress
SAS
Inmarsat Terrestrial
Infrastructure
DoD Network
Exhibit 27: Use Case 2 for Ka-band terminals
Tactical ISR,
Various Sensors,
Full Motion Video(s)
Exhibit 28: Use Case 3 for Ka-band terminals
Long Duration,
High Altitude
Multiple Sensors,
High-Def Video
CONCLUSION
The applications of UAS and
their performance continue
to expand. Investments and
experience have allowed
significant accomplishments
in the UAS realm in a relatively
short period of time. Inmarsat’s
worldwide L-band and
Ka-band communications
solutions provide an excellent
means of supporting BLOS
communications for UAS
platforms. Capabilities
on the Inmarsat satellite
constellations continue to
advance — which expands the
“art of the possible” for UAS
whose missions are enhanced
by BLOS communications. A
reader of this paper will have
gained an understanding
of BLOS options for various
Groups of UAS. Connectivity
performance models for L-band
subscription services, leased
L-band, Ka-band subscription
services and Mil Ka-band
show scalable solutions
across the resilient, worldwide
Inmarsat architecture. This
understanding enables the
formation of reasonable
performance (data rate) and
accommodation (SWaP)
expectations for BLOS
solutions. Unique applications
and advanced terminal
designs can expand or shrink
the available trade space to
a degree, but the information
presented provides a solid
guide for a UAS User seeking
to expand their platform utility
with BLOS connectivity.
While the information in this document has been prepared in good faith, no representation, warranty, assurance or undertaking
(express or implied) is or will be made, nor will responsibility or liability (howsoever arising) be accepted by the Inmarsat group or any
of its officers, employees or agents in relation to the adequacy, accuracy, completeness, reasonableness or fitness for purpose of
the information in this document. All and any such responsibility and liability is expressly disclaimed and excluded to the maximum
extent permitted by applicable law. INMARSAT is a trademark owned by the International Mobile Satellite Organization licensed to
Inmarsat Global Limited. All other Inmarsat trademarks in this document, including the Inmarsat LOGO, are owned by Inmarsat Global
Limited. © Inmarsat Government Inc. All rights reserved. November 2021.