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Case Study:
Satellite Simulator
Satellite
communications have long been
subject to noticeable signal
delays. The lag in satellite
TV broadcasts and phone calls
are examples that many of us
have experienced first hand.
Traveling at the speed of light,
it takes over 200 ms to reach
geosynchronous orbit (GEO) and
back. Even using satellites
at low earth orbit (LEO) of
200 to 400 km, transmission
times between two terrestrial
locations can be significant.
Next generation satellite communications
technologies are now being developed using
much higher bandwidth than ever before.
Defense applications, in particular, will
use gigabit, and even ten gigabit, data
rates. In some cases, “free space
optics” is being researched as a
way to transmit high bandwidth signals
between satellites in space. As a result
of higher data rates, simulating and testing
satellite communications using fiber optic
cables in a traditional lab environment
is increasingly common. The Anue Satellite
Simulator, with precise, controllable
and enormous delay capabilities fits this
satellite simulation requirement perfectly.
In Fall 2004, Anue Systems received an
order from a large DoD contractor for
three ten Gigabit Signal Delay Emulators.
Anue's ten gigabit product platform, called
the "H" Series, delays and impairs SONET/SDH
OC192/STM64, Ten Gigabit Ethernet (LAN
Phy and WAN Phy), and 10 Gigabit Fibre
Channel traffic. SONET G.709 and GigE
FEC data rates are also included.
This customer began testing in early
2005 a simulation of an “Internet
in the Sky” defense shield. Initially,
with a setup of three routers (either
Cisco 15454 or Juniper M320) as geo-stationary
“satellites” and the Anue
Satellite Simulator as the OC192 “links”
between the three satellites, the effects
of latency on high bandwidth communications
between orbiting satellites is being tested.
Since the three satellites will be moving
in relation to one another, the ability
to dynamically vary delay times is essential.
This requirement led to the development
of Anue's “Doppler Shift”
functionality, which is available on all
Anue “H” Series Systems as
an option. Using Doppler Shift, a user
can automatically increase and/or decrease
the delay time injected by the Anue Satellite
Simulator in increments as small as one
part per million (ppm).
After the initial test setup is verified,
this contractor plans to add LEO satellites
to its test bed and, after that, simulated
ground based communication stations. The
total number of links will grow to the thousands,
and data rates, protocols and requirements
between the different nodes will vary. The
result of these multi-year tests will be
a thoroughly validated communications system
that can then be incorporated into actual
satellite and ground station equipment.
About Anue
Systems, Inc.
As a leading provider of innovative network
delay emulators, Anue Systems is the company
that "delays your data." Anue's Gigabit
Ethernet, Fibre Channel and SONET/SDH Network
Impairment and Delay Emulators meet the
needs of organizations that are designing,
building, testing, deploying and using high-speed
fiber optic data networks. Headquartered
in Austin Texas, Anue Systems has built
a team of world-class engineers with expertise
in optical data networking and testing.
For more information, visit Anue's website
at www.anuesystems.com
, email anueinfo@anuesystems.com,
or call 512-527-0453.
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