4A Flashcards
The ___ provides a reliable, high-capacity, quality communications capability in support of peacetime, contingency, and wartime operations.
Defense Satellite Communications System (DSCS)
Specifically, the DSCS provides what?
high availability communications services
DoD manages the satellites with direction from…?
Defense Information Systems Agency (DISA).
Satellites in a DSCS network are considered ___ by users since the cost
of bandwidth and hardware are paid at the Service level.
free
All DSCS satellites have a frequency plan. What is a frequency plan?
A frequency plan is a way to map how frequencies translate up or down to create a full duplex link.
DSCS satellites have ___ channels, or transponders, that are used to transmit and/or receive.
six
Channels 1 – 5 perform a ___ MHz translation frequency while channel 6 performs a ___ MHz translation frequency.
725 MHz
200 MHz
Guard bands are used to prevent interference, so channels are spaced ___ MHz apart.
25 MHz
Guard bands are used to prevent what?
Interference
DSCS satellites operate mainly in the __-band
X
DSCS satellites have a beacon frequency of ___ MHz to locate the satellite in the sky.
7,600 MHz
Each satellite will also produce a ___ to ensure use of the correct satellite. i.e.: 7,604.705 MHz.
pseudo-beacon
The ___ system is a constellation of highly capable military communications satellites that leverage cost-effective methods and technological advances in the communications satellite industry.
WGS (Wideband Global Satellite)
The WGS system is composed of three principal segments:
space segment (satellites), control segment (operators) and terminal segment (users).
What are the DoD’s highest-capacity communications satellites?
WGS Space Vehicles (SV)
Each WGS satellite provides service in both the __ and __ frequency bands, with the unprecedented ability to cross-band between the two frequencies onboard the satellite.
X and Ka bands
WGS augments the ___ Global Broadcast Service (GBS) service through new ___ Ka-band service.
one-way
two-way
Just ___ WGS satellite provides more SATCOM capacity than the entire legacy DSCS
constellation.
one
___ is a constellation of military communications satellites in geosynchronous orbit that are operated by the United States Air Force and provide secure and jam-resistant worldwide communications to meet the requirements of the Armed Forces of the United States.
MILSTAR
___ MILSTAR spacecraft were launched between 1994 and 2003, of which five (5) are operational; the third launch failed, both damaging the satellite and leaving it in an unusable orbit.
six
MILSTAR satellites provide ___, ___, ___ to meet the requirements of the United States military.
secure
jam resistant
worldwide communications
MILSTAR satellites were built by Lockheed Martin Missiles and Space
Corporation, at a cost of $___ million each.
$800
Each MILSTAR satellite has a design life of ___ years.
10
MILSTAR satellites are composed of processing satellites with on-board ___ and ___, a configuration that is inherently more jam-resistant than conventional transponder satellites.
demodulation
switching
___ between the MILSTAR satellites allow worldwide communications without the use of multi-hop ground stations, providing increased anti jam capability.
crosslinks
___ is the protection from EMP effects of a nuclear explosion and it’s a big
component of the military which enables protected SATCOM systems overcome jamming attacks through the use of a combination of Transmission Security (TRANSEC), modulation, and interleaving techniques that hop, permute, and spread the communications data over the usable bandwidth.
Anti-scintillation
MILSTAR systems are comprised of a constellation of geosynchronous satellites that provide survivable, ___, and high assurance, ___ communications capability.
anti-scintillation (AS)
anti-jam (AJ)
The ___ is a joint service satellite communications system that provides survivable, global, secure, protected, and jam-resistant communications for high-priority military ground, sea, and air assets.
Advanced Extremely High Frequency System (AEHF)
The ___ System is the follow-on to the MILSTAR system, augmenting the capabilities of
MILSTAR, and expanding the MILSATCOM architecture.
AEHF
The throughput of the AEHF is ___ times higher than that of the MILSTAR satellites. It has substantially increased coverage area, providing connectivity across naval, air, and land mission warfare.
ten
AEHF is a series of ___ military communication satellites, which supplement the legacy
MILSTAR constellation system.
six
___ satellites provide Extremely High Frequency (EHF) range uplink /
crosslink capabilities and Super High Frequency (SHF) range communications.
AEHF
The AEHF system consists of satellites in space, user terminals and ground-mission control, and associated communication network systems. Together, they enable communications and transfer of data at specified rates ranging from ___ bps to about ___ Mbps.
75 bps to about 8 Mbps
The six AEHF satellites are linked to form a constellation and provide 24-hour-a-day continuous coverage between latitudes ___ south and ___ north.
65 degree
Developed for the U.S. Navy by Lockheed Martin, the ___ is revolutionizing secure Ultra-High Frequency (UHF) SATCOM for mobile forces.
Mobile User Objective System (MUOS)
____ radio terminal users – supporting mobile, tactical ground, sea, or air operations – can seamlessly connect around the globe and into the Global Information Grid (GIG), as well as into the Defense Switching Network (DSN).
MUOS
MUOS’ new capabilities include ___ crystal-clear voice, video, and mission data on a high-speed Internet Protocol-based system.
simultaneous
The MUOS network is sustained by an initial configuration of ___ orbiting satellites and ___ relay ground stations.
4
An on-orbit spare, ___ , will ensure the network is always available to support U.S. and allied mobile forces, as well as actively supporting the legacy UHF system.
MUOS-5
Commercial Satellite communications operate in the __-band and __-band.
C
Ku
One way to distinguish between military and commercial satellites is by their name. Commercial satellites have the term “___” in their name.
SAT
Keep in mind that when using a commercial satellite your unit pays
for the ___ ___.
access time
The ___ is a satellite-based radio navigation system owned by the United States government and operated by the United States Air Force.
Global Position System (GPS)
The Global Position System (GPS) was originally called…?
Navstar GPS
It is a global navigation satellite system that provides geolocation and time information to a ___ receiver anywhere on or near the Earth where there is an unobstructed line of sight to four or more ___ satellites.
GPS
What blocks GPS signals?
Obstacles such as mountains and buildings
The United States government created the system, maintains it, and makes it freely accessible to anyone with a…?
GPS receiver
Provides support for the operation, control, and maintenance of a variety of United States Department of Defense and some non-DoD satellites. This involves continual execution of Telemetry, Tracking, and Commanding (TT&C) operations.
Air Force Satellite Control Network (AFSCN)
In addition, the ___ provides prelaunch checkout and simulation, launch support, and early orbit support while satellites are in initial or transfer orbits and require maneuvering to their final orbit.
AFSCN
The ___ provides tracking data to help maintain the catalog of space objects and distributes various data such as satellite ephemeris, almanacs, and other information.
AFSCN
