Tool for a Crowded Spectrum
Written by Michael Burnett
Clear battlefield communications depend on the ability of friendly forces to transmit messages back and forth among blue force units. But on today’s battlefields in Southwest Asia, a lot of electronic devices are competing for the airspace through which radio frequencies travel, sometimes creating interference in vital communications.
To combat that problem, the Army Communications Electronics Research, Development and Engineering Center (CERDEC) has been developing the Coalition Joint Spectrum Management Planning Tool (CJSMPT). The CERDEC Space and Terrestrial Communication Directorate is working on CJSMPT, a joint capabilities technology demonstration program, with the goal of deploying some capability for avoiding potential electronic inference early next year.
“CJSMPT is a modeling and simulation- based analysis tool that can be used for emission planning to analyze and determine the spectrum impacts of a particular mission in a particular area of operations,” explained Frank Loso, CJSMPT program manager and chief engineer of the directorate’s Antennas and Spectrum Analysis Division.
“One specific focus is on determining potential interference due to electronic warfare operations on the blue force communications spectrum,” Loso said. “In addition to identifying potential interference, CJSMPT provides a spectrum deconfliction capability that nominates frequency assignments for blue force communications systems in a way that mitigates that potential interference.”
Development of CJSMPT is divided into two phases. In the first phase, CERDEC is focused on deconflicting terrestrial emitters on the battlefield. In the second phase, the agency will expand CJSMPT capabilities to include airborne emitters and satellite communications.
The first phase of the program has focused on combating interference from active and passive radio frequency emitters on the ground, Loso elaborated. Those emitters include not only communications systems but also sensor systems and electronic warfare systems. Active emitters also may produce intended and unintended emissions, complicating the effort to avoid conflict with their emissions.
CJSMPT takes a look at emissions from those various devices and determines the potential impact of any interference they may generate. One potential source of interference that took precedence for CJSMPT engineers were jammers intended to counter IEDs.
IED PRIORITY
Since many insurgents in Iraq use radio transmitters to trigger IEDs, the Department of Defense has been developing devices that can jam those radio transmissions. Those jammers, however, may also interfere with blue force communications as an unintended side effect.
“The top priority for those jamming systems is to counter the threat,” Loso remarked. “However, we are concerned with the potential impact of that sort of emission on force communications. That’s one of the things that CJSMPT does.” Deconflicting potential interference from counter-IED jammers became a major goal of CJSMPT once the depth of the problem was understood, added Mahbub Hoque, chief scientist and division chief of the Antenna and Spectrum Analysis Division.
“When we started this program, we intended to address battlefield interference issues. As we progressed and tried to establish the utility of this tool, we found there was more of an intense need to address the communications issues for jammers used to detect IEDs. The jammer was causing problems,” Hoque said. “So we redirected this program a little bit to address the immediate need in the battlefield environment to the interference issues between jammers and communications systems.”
CJSMPT is a software tool with two main components. One component is the analysis tool itself. The second component is a comprehensive database that contains spectrum information, force structure information, and emitter characteristics. Emitter characteristics include such information as frequency assignments, emitter locations and related information.
A team of personnel from Central Command, Joint Forces Command and Product Manager NetOps traveled to Iraq to demonstrate CJSMPT to Army and Marine Corps units stationed there. The team, carrying laptops with CJSMPT loaded, left in mid- September and was scheduled to return as this issue was going to press, according to Lieutenant Colonel Russ Leaphart, deputy military director of the Space and Terrestrial Communications Directorate.
“We will then be able to get some really good feedback from guys on the ground in theater right now as to how well this tool works, how well it helps them do their job, and some things that we can do to improve the tool,” Leaphart said.
That team will file a report on its findings upon its return. In addition, the Joint Interoperability Test Command (JITC) will run a test event on CJSMPT at Fort Huachuca, Ariz., in December. CERDEC will evaluate the findings of the field team report and the test reports and make a decision on whether or not to deploy phase one of the CJSMPT software to Iraq and Afghanistan early in 2008.
“Phase one would be deployed, pending a positive decision at the first of the year. The phase two development effort would still be ongoing. We are looking for a phase two deployment sometime in summer 2008,” Leaphart noted.
Phase two has several objectives, he continued. One objective is to boost the overall capabilities and functionality of CJSMPT.
SPECTRUM MANAGEMENT
The second objective is to declare the system ready to serve as the first increment of the Global Electromagnetic Spectrum Information System (GEMSIS), a larger spectrum management program run by the Defense Information Systems Agency (DISA). JITC would run another operational test in 2008 to demonstrate that CJSMPT meets the GEMSIS requirements.
“So we are really building the foundation for the GEMSIS development effort,” Leaphart declared. “We are building increment one and building in the right pieces and parts. That’s a lot of what phase two is—building in the blocks that allow the smooth transition into the GEMSIS effort.”
Once DISA took ownership of CJSMPT and rolled it into GEMSIS, CERDEC would at least temporarily suspend any development efforts under CJSMPT. PDM NetOps, under the Program Executive Office Command, Control and Communications Tactical (PEO C3T), would take responsibility for sustainment of CJSMPT for a two-year time period while DISA starts up the GEMSIS program.
Hoque pointed out that CJSMPT also could lend itself to a future program at CERDEC. “We have proposed a system called Cognitive Network and Radio Systems,” Hoque revealed. “That would start up in fiscal 2009 and fiscal 2010. There is a potential application of this system to roll into that program, which would detect radio frequencies in the environment and automatically resolve interference issues.”
CJSMPT has been developed under a contract awarded by CERDEC to Lockheed Martin. The contract, valued at $5.2 million with options, would “automate and accelerate spectrum planning, making it easier for troops to communicate while avoiding interference from jamming operations,” according to a press release from Lockheed Martin Advanced Technology Laboratories. “In the short term, CJSMPT will immediately optimize spectrum use to mitigate the effects of jamming on coalition military systems,” said CJMSPT principal investigator Bill Kline. “In the long term, it will provide an automated planning tool to manage battlefield spectrum much more efficiently.”
The goal of CJSMPT is to help planners manage battlefield spectrum through a three-dimensional display of real-time frequency use in the battlefield environment for land, air and space emitters. CJSMPT coordinates radio frequencies within available spectrum, according to the contractor, thus clearing the way for complete communications between commanders and field assets.
CJSMPT runs a simulator in faster-thanreal time to predict and visualize interference generated by forces in the battlefield space.
“Prior to this tool, military planners predicted interference based on static analysis, which tended to cause overly pessimistic solutions and loss of opportunity for spectrum reuse. By coordinating all emitters and knowing their locations in a region, spectrum planners will now be able to boost reuse and significantly increase communication bandwidth to coalition forces,” the company stated.
A paper published by Lockheed Martin and CERDEC describes the CJSMPT architecture as consisting of five key components:
• Spectrum manager to coordinate system operation and execute algorithms to de-conflict radio frequency interference.
• Communications effects simulator to simulate mission scenarios and to predict conflicts.
• Visualizer to present spectrum use, including the impact of electronic warfare.
• Spectrum knowledge repository, which is the database described by Loso to support mission simulation.
• Framework to provide open service-oriented architecture with mechanisms for component data exchange.
Team members include Alion Science and Technology and SYColeman, in cooperation with the Army Battle Command Battle Lab, Fort Gordon, Ga.; the Joint Spectrum Center; and Penn State University. ♦
