The Emerging World of JTRS

By Charlotte Adams | March 1, 2002
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This spring, possibly this month, the U.S. armed forces will enter uncharted territory. If all goes as planned, the Army will award the first chunk of a program with an ambitious end state: a single tactical radio family for air, land and sea platforms.

The U.S. military is expected to replace today’s 750,000 tactical navigation, positioning, location, identification, air/ground, air/air, ground/ground and satcom radios–25 to 30 radio families, in all–with 260,000 Joint Tactical Radio System (JTRS) units. JTRS will provide interoperable voice, data and video communications in an attempt, as the Joint Program Office puts it, "to change radios from specific systems to an RF [radio frequency] utility."

The contract at hand is for "Cluster 1" development, integration and initial procurement of Army and (a small number of) Air Force radios. This award–with early production options for as many as 10,000 units–could be worth close to $1 billion, says Boeing, which is going head to head with Raytheon on JTRS. Raytheon estimates that total procurement under Cluster 1 could reach more than 106,000 units, largely through a follow-on production award. The program is "the foundation for next-generation tactical communications," says Jim Olivo, Boeing’s capture team leader.

Battlefield Browser

Managed by the U.S. Army, Cluster 1 will procure radios primarily for Army purposes–helicopters, tanks and ground vehicles–with about 560 units provided for Air Force tactical air control parties, according to Raytheon estimates. Fielding is expected to begin in late 2006.

JTRS will use software programs to "transfer voice, data, and video through the battlefield equivalent of an Internet browser, complete with plug-ins that allow motion and voice to move with the ‘web’ pages," says Dick Hitt, director of business development and strategic planning, Raytheon Radios and Terminals.

Army helicopters are scheduled to be equipped with JTRS first. Army aviation lacks the EPLRS (enhanced position locating and reporting system) radios that ground forces have, says Doug Grice, director of business development for Army programs, Raytheon Radios and Terminals. A software-defined EPLRS waveform is on the must-do list for Cluster 1.

The Navy plans to develop non-mobile units. Industry officials expect the Navy could release a request for proposals (RFP) by September 2003 and award a contract the following year. The Navy also is positioned to influence program evolution. The JTRS program has selected the Space and Naval Warfare Systems Command to support test and evaluation of JTRS technology.

Handheld/manpack and "fast mover," airborne clusters also are expected. Notional space, subsurface and homeland defense clusters also are mentioned in government program briefs. At this time, however, only Cluster 1 has been fully defined.

Software-programmable radios promise the ability to perform future upgrades without changing the underlying hardware, which can become more generic than currently fielded, single-waveform, voice or data radios. JTRS radios can be tailored to individual user needs through software, the thinking goes. Among the technologies that promise to enable this plan are higher-speed digital signal processors, improved analog-to-digital converters, and middleware standards such as the common object request broker architecture (CORBA), which allows hardware/software separation.

Raytheon’s team includes the following:

  • SAIC for system engineering tradeoff analysis, modeling and simulation;

  • General Dynamics for software-defined radio and manufacturing expertise;

  • ITT for wideband networking technology and manufacturing experience;

  • TRW for engineering support;

  • Thales for HF communications expertise; and

  • ViaSat for Link 16 experience.

Boeing’s side includes TRW for engineering support and integration and Rockwell Collins and BAE Systems/Harris for airborne and ground systems development, as well as manufacturing expertise.

JTRS Waveforms

The government will select a "prime system integrator," who will qualify two radio vendors. (In Raytheon’s case the vendors will be ITT and General Dynamics; in Boeing’s case, Collins and BAE/Harris.) These companies will then square off against each other for future hardware buys.

"This is all about keeping the industrial base up and working," says Hitt. The prime integrator also will develop or procure software for 21 waveforms, including the new, scalable wideband networking waveform (WNW); obtain form, fit and function specifications from the services; and integrate the units into the platforms.

WNW, the key JTRS waveform, eventually will supersede all of the others. WNW will allow many JTRS radios to communicate with each other, as they move around the battlefield, much as computers in an office communicate over an Ethernet local area network (LAN), explains Stan Griswold, director of advanced communication systems for Raytheon team member, ITT. The hardest piece of the contract is "ensuring you have the software and hardware architectures integrated via the WNW," Olivo says. JTRS radios will operate over frequencies from 2 MHz to 2 GHz.

JTRS is the first software-definable radio using an open, published architecture. The digital modular radio (DMR), the only software-defined radio in production, does not use an open architecture, Raytheon says. DMR, a Navy radio developed by a Motorola unit that’s now part of General Dynamics, allows up to four radio channels. Operators can establish and change features, such as bandwidth, modulation, error control, security and waveforms, through a PC-type interface.

JTRS’ software communications architecture (SCA), comparable to an operating system on a personal computer, was developed by Raytheon and members of a Raytheon consortium, including ITT and Rockwell Collins. SCA describes the hardware and software design criteria necessary to assure that waveforms and radio services execute properly, Hitt says.

With JTRS "you can download new waveforms," says Grice. "It’s like downloading AOL Version 7." Vastly oversimplified, the user loads the new software, reboots and pushes an icon.

Bridging the Gap

While radios are being fielded, JTRS will employ a "bridging" concept. A JTRS radio can "connect one kind of legacy radio to another by translating the waveform protocol of the first [such as SINCGARS, the Army’s single-channel ground/airborne radio system] to the waveform protocol of the second [such as EPLRS]," explains Hitt. Bridging allows a JTRS unit to be a "middle man," connecting two radios that were not designed to communicate with each other. A JTRS also could allow a commercial cell phone user to talk to a military radio, he says.

Using JTRS will create a virtual network, through which ships at sea could communicate with forward platoons. "JTRS is about networking and network services that give [users] the ability to open a channel," says Paul Blackwell, Raytheon’s vice president of Army command, control and communications programs. "The network is key," Olivo agrees. "It will improve the flexibility and mobility of the future battlefield."

But networking protocols will be a major challenge, according to a government overview. They must support a range of services, such as link quality discovery, automatic network reconfiguration, quality of service guarantees, precedence and priority marking, and automatic routing and traffic relay, with minimal overhead. The military today typically uses static, pre-planned networks with only limited ability for "adaptation and forwarding between networks via gateways," the government overview says.

Another challenge is software portability and reuse. Hardware gravitates toward specialized components, such as application-specific integrated circuits (ASICs) and field programmable gate arrays (FPGAs), for performance reasons. But this trend makes software portability and reuse more difficult. Other challenges include security features, interference mitigation, test and certification, spectrum management, integration procedures, and operational test and evaluation.

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