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Exercise Reveals Information Systems Interoperability Issues

August 2005
By Martin E. Mendoza and Kelly Straub

11th Signal Brigade soldiers transmit test messages via their data package at Defense Department Interoperability Communications Exercise 2005. A typical data test involves approximately 5,000 images, e-mail messages, file transfers and Web server requests.
Greater use of commercial technologies does not guarantee military success.

The pace of fielding technology is increasing so quickly that testing, training and maintenance personnel are having a hard time keeping up. To address this challenge, one command is using annual exercises to ensure that communications equipment is interoperable with fielded equipment when it arrives in warfighters’ hands.

The Joint Interoperability Test Command (JITC), a field command of the Defense Information Systems Agency (DISA) and the U.S. Defense Department’s sole joint interoperability certifier, hosts the Defense Department Interoperability Communications Exercise (DICE) annually to generate joint interoperability certifications. The department established DICE as an event supported by the Joint Staff and the U.S. Joint Forces Command. As the sole Defense Department exercise in which the primary purpose is to generate joint interoperability certifications, DICE both paves the way for communications interoperability and uncovers problems that may arise even with a successful interoperable deployment.

DICE reduces the warfighters’ risk of operational failure by aggressively testing new versions of software, equipment and employment techniques in a realistically replicated joint task force (JTF) communications network. The exercise allows participating warfighters to develop and improve their proficiency in information systems related mission-essential tasks as well as tactics, techniques and procedures. DICE emphasizes the three components of interoperability— forces, procedures and equipment— and it affords significant training opportunities for thousands of participants.

From its simple birth as a basic five-circuit switch network in the late 1980s, DICE has evolved into a network-centric, advanced technology joint certification exercise with more than 30 switch systems geographically dispersed over several time zones. DICE focuses on assessing the degree of interoperability of a typical JTF using new versions of hardware and software employed in a joint transmission, switching and information systems network. It employs a realistic joint architecture that provides the necessary opportunities to exercise and evaluate voice, data and video interfaces that are critical to split-base operations. The exercise also is evolving to include federal, state and local agencies involved in the global war on terrorism.

This year’s event was sponsored by the U.S. Northern Command (NORTHCOM) and had a homeland security focus. In addition to NORTHCOM, participants included personnel, along with communications equipment, from each of the services; the U.S. Central Command (CENTCOM); the Space and Naval Warfare Systems Command; the U.S. Department of Homeland Security/Federal Emergency Management Agency (FEMA); the National Guard Bureau; state and local agency first responders; and coalition partners such as Canada. Vendors also brought systems and equipment for testing. Over a period of eight weeks, 32 interoperability tests were completed.

The JITC believes that many forces are gambling on their communications interoperability, and the command hears many reasons from them. Some force commanders say the equipment in question should work because it conforms to existing industry-accepted standards. Others contend that gear will be effective because it is being used by the commercial world without any problems. Conformance to standards does not guarantee interoperability, JITC officials emphasize, and the combat zone is not the commercial world. Industry-accepted standards may not suffice in 125-degree heat, and the employed tactical network does not necessarily resemble the commercial world, they add.

DICE has revealed several trends over the past four years of testing. One of the most prevalent trends is that the pace of technology being fielded for or by the warfighter continuously has outpaced the training and maintenance needed to operate that technology. Contractor and vendor specialists increasingly are called upon to install, operate and maintain new systems and equipment, at times even during final testing for interoperability. Soldiers, sailors, airmen and Marines are almost always involved in testing, but for the most part they are learning the systems and equipment while testing is taking place. Warfighters involved with testing either become the core of a very elite few that go on to test even newer systems and equipment, or they are deployed to train units that are receiving the equipment. Even when deployed systems from one service remain unchanged from one year to the next, technology upgrades to systems of other services require retesting to ensure interoperability still exists between the systems.

The trend to use Ku-band satellite systems that provide greater bandwidth also is increasing. During DICE 2002, approximately 60 percent of the systems and equipment were tested over X-band satellite systems, with the remaining 40 percent tested over Ku-band terminals. During DICE 2005, this ratio had reversed to 80:20. Increasing information requirements have spurred technological innovations in the areas of voice, data and video that are appealing to warfighters but that require higher bandwidth. Very small aperture terminal (VSAT) satellite systems using time division multiple access (TDMA) technology are becoming more popular among warfighters. VSAT TDMA systems allow multiple stations to share satellite bandwidth on demand. DICE 2003 saw one such system tested. For DICE 2005, CENTCOM, the Joint Communications Support Element, the U.S. Air Force and Navy tested four systems.

Maximizing bandwidth availability is another developing trend. Testing of data accelerators, voice over Internet protocol and everything over Internet protocol systems has increased significantly over the past three years. Instead of dedicating bandwidth to voice, data, video, intelligence or other applications, warfighters are looking for ways to maximize the bandwidth available by using systems and equipment that employ one or two data streams for all their requirements. Unfortunately, many of these systems have restrictions on use for command and control purposes because of multilevel precedence and pre-emption, quality of service, and class of service issues yet to be resolved.

Engineers install a Federal Emergency Management Agency secondary Ku-band satellite antenna. The use of Ku-band satellite links is increasing considerably among military and civilian government communicators.
DISA is working aggressively on policies and procedures that eventually will clear the way for the deployment of these types of systems and equipment. In the meantime, DICE allows warfighters to test these systems in realistic networks, to provide valuable information to defense communications policy makers and to mitigate risks for the warfighter.

One of the more significant and operationally relevant tests that occurred during DICE 2005 was interoperability testing of the Secure Terminal Equipment (STE). The JITC, in response to real-world operational reports of difficulty in completing secure STE calls, particularly in the CENTCOM area of responsibility, used the DICE network to conduct extensive tests.

Testing focused on the STE version 2.4 release and evaluated the Secure Terminal Unit III (STU-III) and Future Narrowband Digital Terminal signaling modes, strategic and deployed commercial-off-the-shelf (COTS) two-wire interface, and legacy Mobile Subscriber Equipment/Tri-Service Tactical with tactical wedge using two- and four-wire interfaces. The preliminary results indicate that STE version 2.4 is slightly better at completing secure calls than previous versions. Examiners also discovered that the success of completing a secure call via any STE version depends on the network used. Completing secure calls across a mixture of deployed COTS switch systems that use pulse code modulation and legacy tactical equipment that use continuously variable slope delta modulation will continue to pose challenges and will remain a concern.

The operational tempo (OPTEMPO) of DICE is determined by the testing requirements. Testing can be paused, accelerated, decelerated or repeated as necessary. The test network is dynamic in the sense that all or part of the network can be reconfigured to resolve critical interoperability issues. In more typical exercises, scenarios and exercise timelines drive the OPTEMPO. In the event of a communications or interoperability failure, the typical exercise will not be stopped to figure out what went wrong. It is up to the signal unit to figure it out and catch up. Some would argue that this is more realistic, but the JITC believes that the testing ground should not be the battleground, especially when there are events such as DICE to mitigate those risks.

The planning, acquisition and warfighter communities receive feedback from DICE in several ways. The joint communications control center chairs daily teleconferences in real time to facilitate effective and efficient use of test resources and to determine the degree to which exercise objectives are being met. These conferences are conducted using the Next Generation Collaborative Service—the Defense Department’s WebEx—and a voice conference bridge to share ongoing results with interested parties. The JITC publishes an overall DICE Executive Test Report as well as system-specific interoperability assessments and interoperability certification reports. These reports are usually available at the JITC Joint Interoperability Tool Web site approximately two months after conclusion of the exercise.

Units do not have to deploy to Fort Huachuca, Arizona, to participate in DICE, although many do so to exercise their deployment procedures and to maximize their opportunity to work side-by-side with JITC subject matter experts and other service and vendor experts. As long as the JITC can establish and sustain reliable connectivity to participants via landlines, satellite links, the Defense Research and Engineering Network or some other means, remote units can be part of the DICE exercise.

The DICE architecture is protected in that DICE participants operate in the network as they would in the real world, but they are not physically connected to any live Defense Information System Network (DISN) services. DICE encourages the services to have actual operational units install, operate and maintain the equipment and systems used in the exercise. This creates an operationally relevant training opportunity for the command. These configurations are representative of those used in real-world combat and contingency operations by the warfighting community, and they provide sufficient data to assess the interoperability of the systems and to determine whether previously experienced anomalies were corrected. Once the system or equipment is certified as interoperable, it is allowed to connect to the DISN.

DICE 2006 is scheduled to be conducted February 2006 through March 2006 at FortHuachuca and at various locations nationwide. Although involvement in DICE is voluntary, participation in the 2006 exercise is expected to increase substantially.


Martin E. Mendoza is a telecommunications specialist at the JITC responsible for DICE network integration, coordination and planning. Kelly Straub is an electronics engineer at the JITC responsible for the homeland defense/homeland security portion of DICE and land mobile radio testing.


Web Resources
JITC Joint Interoperability Tool: