DOD integrates best sim tools -

The Defense Department is putting the final touches on specifications for a modeling
and simulation system that will integrate Army, Navy and Air Force systems into a seamless
battlefield training and analysis tool.

The Joint Simulation System (JSIMS) will let units from different services hold joint
simulated training exercises. The framework for a common systems architecture blends the
service-unique features of different mission models into an interoperable whole.

"A common integrated synthetic environment will mean the same thing to the land
warrior as it does to the air and naval warrior," said Navy Capt. Drew Beasley,
manager of the JSIMS program.

JSIMS will cost DOD $150 million through 2003. But each service is picking up part of
the tab by funding its own next-generation models: the Army's War Simulation-2000, the Air
Force's National Air and Space Model and the Navy's Maritime System.

Instead of the Army, Navy and Air Force trying to represent the other services'
functions and requirements in their own models, JSIMS' synthetic environment will provide
an infrastructure for the services to integrate their platforms and mission-space needs.

"Things from the sea, land, air and space will all have a common time that they
start, stop, enter and exit a game of play," Beasley said. "Right now, when you
do those things, everything must be totally prescripted, otherwise they don't have clean
entrance and exit points. And without that, the simulation falls apart."

For example, the Navy will provide simulations of ships, the Army simulations of tanks
and the Air Force simulations of aircraft fighters.

"The Army should not have to build air representations or air mission-space
objects," Beasley said. "By the same token the Air Force should not have to
build land objects."

JSIMS will ultimately provide an environment "to jointly train, educate, develop
doctrine and tactics, formulate and assess operational plans, assess warfighting
situations, define operational requirements and provide operational input to the
acquisition process," according to the JSIMS operational requirements document.

The services' existing stovepipe systems cannot talk to each other because the Army's
Core Battle Simulation system uses a hexagon-based grid to simulate terrain, while the
Navy's Research and Evaluation Simulation Analysis system uses latitude and longitude
measurements, and the Air Force's Air Warfare System has a third representation.

The JSIMS architecture will accommodate diverse reference points. Each service will
develop its own software with integration points and common formats so that each service's
unique, specific simulations can be represented across a common backdrop.

"We've tried to coalesce requirements from the various services under a single
software segment specification," Beasley said. "I've been working under an
operational requirements document for some time, and the update is being finalized."

But given the high degree of interoperability required, JSIMS software development will
be particularly challenging, Beasley said. His team has begun the daunting task of
developing more than a million lines of software code for the integration.

"For our initial software build, we're using SunSoft Solaris and Solaris NT as
part of our working effort," Beasley said.

TRW Inc. of Cleveland last December won a seven-year, $69.2 million contract to provide
systems integration and development for JSIMS. TRW's subcontractors include Aegis Research
of Huntsville, Ala., Aurora Simulation Inc. of Reston, Va., Matcom 2 of Alexandria, Va.,
MRJ of Fairfax, Va., Science Applications International Corp. of San Diego and Sparta Inc.
of Laguna Hills, Calif. SAIC is developing the JSIMS core infrastructure and system
architecture.

"We're looking at a layered systems integration architecture," Beasley said.

The JSIMS team has not set a hardware specification, but DOD wants the software
developers to "build a veneer that is open and adaptable to just about any
system," he said.

JSIMS will follow a distributed system rather than a massively parallel approach, he
said. The individual services will decide what hardware to use.

"We're trying to stay well away from large computers or massively parallel
computers because I want to be able to distribute this out to field units wherever they
might be," Beasley said. "We're trying to keep it an open system for maximum
portability across systems hardware. From ships at sea to garrisons, there's a host of
equipment that we're going to have to tie into."

Now many of the models run on VAXes and large-scale mainframes. "That limits the
distributability and the frequency of use of the models," said David Pratt, JSIMS
technical director. "What we're developing is a distributed computing architecture in
which I can build a cluster of Unix workstations over a high-speed network."

When the JSIMS team was planning the simulation system, it realized it had to move away
from supercomputing to make the system easily usable across the services.

"It boils down to two fundamental issues: cost and efficiency," Pratt said.
"If I always need a supercomputer to run the model, I'm going to need two
supercomputers standing by at all times. But if I use a distributed system of
workstations, I can tailor my resources much better."

The JSIMS charter requires that the program comply with the department's high-level
architecture requirements, which the Defense Modeling and Simulation Office developed to
increase interoperability and lower development and operating costs. A major objective of
the JSIMS program is to cut the services' simulation operation and maintenance costs by
two-thirds.

The services had developed software, called the aggregate-level simulation protocol,
that acted as an interface among many simulation programs. But the personnel and computing
power required to support all the simulations was taxing, Beasley said.

The legacy simulation systems developed mostly in the early 1980s use Fortran and
require a lot of manual code modification.

There is a strong trend among government simulation programs to use C++ instead of Ada,
for which DOD recently lifted its mandatory-use requirement.

"We do have one or two partners that are using Ada 95, and there are Java
applications that we're looking into," Beasley said. "But, as with most of our
partners, our predominant architecture will be in C++."

The services use multiple computer programming languages to develop the Army's WARSIM
2000, the Air Force's NASM and the Navy's Maritime System models.

"We're trying to do this on a framework-based system where we can actually get
significant benefit from object-oriented design and programming, and those don't easily
translate across language boundaries," Pratt said. "This is one thing we're
going to be figuring out for the life of the program."

A software design review called Build Zero is scheduled for next March. It will not
have the robustness of a joint exercise-level simulation, Beasley said, but Build Zero
will demonstrate that the basic architecture and software works.

JSIMS' first test is scheduled for May 1999 and will be evaluated in December 1999 in
conjunction with Unified Endeavor, a U.S. Atlantic Command exercise held at its Joint
Training Analysis and Simulation Center (JTASC) in Suffolk, Va.

JSIMS will replace the simulation training environment in use at USACOM's JTASC
facility, the Joint Warfighting Center at Fort Monroe, Va., and other facilities. Besides
joint task force simulations, DOD will also use JSIMS for rehearsing peacekeeping and
humanitarian missions.