Military Embedded Systems - Fall 2005 - Volume 1 Number 2

In the System
better compression ratios than the widely
used MPEG-2 standard. The card then
streams compressed data over the PCI bus
to the host SBC. On the host, the MPEG-
4 stream is encapsulated and passed to a
network connection using UDP. Remote
display clients supplied with the bundle
can then decompress and display the
decoded video streams. It should be noted
that this is an FPGA-based system, reaping
all the benefits of FPGAs that we’ve
been describing.
Surveillance UAV example
Battlefield surveillance UAVs such as the
Altair Predator B variant (Figure 2) are
good examples of where packaged PMCbased
FPGAs like the TS-MPEG-4 could
be used for video capture and compression.
This class of UAV usually flies at
low to medium altitude over a battlefield
or other area of particular interest and
carries a number of video and, possibly,
high-resolution single-shot cameras for a
more detailed view of individual objects.
The UAV will be controlled from a ground
station that receives images from various
cameras and displays them for analysis
by the ground crew. The images may
then also be relayed further up the command
chain to build a complete tactical
picture of the battlefield. The downlink
from the UAV to the ground does not have
the bandwidth to transmit all the video
streams directly from the cameras in real
time, driving the need for compression.
The mission computer for such a UAV
is likely to be implemented using COTS
VMEbus or CompactPCI modules.
Because of the limited space, weight,
and power budgets available in a UAV,
3U CompactPCI would again be an ideal
format choice for the mission computer.
FPGA-based PMC modules for video
compression could be mounted on a host
SBC or could occupy 3U slots using carrier
cards. Video streams direct from
the cameras in RS-170 format would be
converted to MPEG-4 by the FPGAs,
then encapsulated and downlinked by the
mission computer for any of the groundbased
operations required.
The FPGA with its unique and flexible
architecture looks set to replace many of
today’s dedicated DSP solutions where
its parallelism and aggregate throughput
make possible big reductions in real estate
and cost. Equally, the cost of time-todeployment
is becoming a critical factor
for both the government and system integrator,
and FPGA-based solutions often
provide benefits as well. The availability
of bundled, application-oriented COTS
solutions, even though they may require
minor customization for a particular enduse,
promise to bring new FPGA-based
DSP systems online faster and at lower
cost.
Duncan Young has worked in the
defense industry for almost 40 years.
Duncan was part of the management
buyout team that formed Radstone
Technology, and he initiated product
development of conduction-cooled
VMEbus modules. He has also served on
a number of standardization committees.
Duncan is now an independent
consultant and writes this column on
behalf of SBS Technologies.
For more information, contact:
SBS Technologies
2400 Louisiana Blvd. NE, Ste. 5-600
Albuquerque, NM 87110
Tel: 505-875-0600
Website: www.sbs.com
Figure 2
18 / October 2005 Military EMBEDDED SYSTEMS