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Internet in the Sky
UCLA Researchers are Developing a Mobile, Distributed,
Wireless Network
By David Brown and Marlys Amundson
With a growing number of unmanned vehicles taking up positions on
the modern battlefield, UCLA researchers are designing a portable,
rapidly deployable network that will allow these robotic agents
to communicate.
The Multimedia Intelligent Network of Unattended Mobile Agents (Minuteman),
a portable airborne network, will provide local communications for
the increasing array of unmanned air vehicles (UAVs) and unmanned
ground vehicles (UGVs). According to Mario Gerla, UCLA professor of
computer science in the Henry Samueli School of Engineering and Applied
Science, this agile, dynamic Internet in the sky will support the
demanding communications requirements of unmanned missions.
Gerla, along with electrical engineering professor John Villasenor,
heads the $11 million, five-year project funded by the Office of Naval
Research. The project is part of a program on Intelligent Autonomous
Agent Systems overseen by Allen Moshfegh for the Office of Naval Research.
"Minuteman will enable the Navy to bring a fully networked force to
the battlefield," Gerla says. "It will be the glue that holds together
supporting technologies such as mission planning, path planning, reasoning,
decision making, and distributed real-time computing and control."
A network like the one they are developing could also aid emergency
workers responding to natural or man-made disasters. "The system could
be used in areas where people cannot go, whether because of chemical
concerns or adverse environment conditions (e.g., extreme heat or
cold)," notes Gerla.
The UAVs will be arranged in different layers in the network. Explains
Gerla, "the lowest will provide backbone functions, and higher layers
will connect to the Internet and ships at sea. High level UAVs will
also assist in location determination for the static drones as GPS
can be jammed in battlefield conditions."
Also involved in the Minuteman project are UCLA electrical engineering
professors Babak Daneshrad, Izhak Rubin, Gregory Pottie, and Mani
Srivastava, and computer science professor Rajive Bagrodia. These
researchers are developing all of the system layers - from advanced
programmable radios to video encoding applications.
Designing such a network, however, presents a number of challenges.
The first challenge is handling a vast array of agents, some moving
at speeds of several hundred miles per hour. "The traditional Mobile
IP approach requires continuous re-registering of the mobile and will
not scale up to such a large number of mobile agents moving at such
high speeds," Gerla explains.
To meet this challenge, UCLA researchers are developing an addressing
system that will exploit the fact that the vehicles usually will be
moving in teams. In the new scheme (called LANMAR), the address of
each agent will include the name of its team. For each team, only
the team leader (the landmark) is tracked, making it easier and faster
to determine the location of any given vehicle.
In addition to their individual duties, the unmanned craft will be
able to support multiple functions. For instance, some of the UAVs
can be used as a node on the network, for reconnaissance, and also
as a weapon.
The
UAVs gathering intelligence at the front must be able to transmit
multimedia streams of video while the network is in motion, and
with the bandwidth capability fluctuating from high to low. Traditional
quality of service methods do not meet these specialized needs,
so UCLA researchers have replaced the concept of guaranteed quality
of service with that of "adaptively renegotiable" quality of service.
"The video signal must be dynamically adjusted to the available bandwidth,"
explains Villasenor. "We are developing innovative, flexible video
encoding schemes that will allow the system to accurately acquire,
compress, and transmit images of the area under surveillance."
Additionally, automatic target recognition data must be received with
extremely tight time constraints. UCLA researchers are devising a
distributed database that can provide global information about assets
in the battlefield, as well as video images captured during routine
surveillance. The database will supplement the UAV and sensor-image
data with stored information, reducing time to target detection and
recognition. Dynamically reconfigurable software for the sensors and
rovers will allow for automatic recognition of enemy targets in new
conditions.
The network in the sky the researchers are developing must also be
distributed and fault tolerant in order to adjust to failures caused
by natural causes or enemy actions. "If one plane goes down, we don't
want to lose the whole network," Gerla says.
The research team is developing a novel simulator platform on which
to test the network components. Villasenor is directing the assembly
of a sophisticated test bed that will integrate and demonstrate successful
operation of a network of sensors, robots, and miniature helicopters.
"The test bed allows us to deploy the algorithms, and show that the
system we have designed can work successfully," explains Villasenor.
The Minuteman project is carried out within the Center for Autonomous
Intelligent Networks and Systems (CAINS), a center recently established
in the School under the sponsorship of the Office of Naval Research
(ONR). One of the goals of CAINS is to leverage the commonality of
models and methodologies in the area of intelligent agents and networks
across several different fields, from engineering to medicine, biology,
and social sciences. The Center will explore fundamental theory issues
in autonomous intelligent networks and systems. It also will target
applications in several disciplines including communications systems,
controls, wireless self-configuring ad hoc networks, battlefield networks,
biologic systems, and related areas.
Please see http://www.cains.cs.ucla.edu
for additional information on the Center, http://www.cs.ucla.edu/NRL/
for more on Gerla's work, and http://www.ee.ucla.edu/faculty/bios/villasenor.htm
for more on Villasenor's work.
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