CHIPS Articles: The U.S. Military’s Joint Tactical Radio System

The Vision

Lengthy details of the JTRS program history can be found in numerous public references, but a brief recap of that history provides a valuable foundation for this discussion. The genesis of the program lies in the concept of exploiting advances in technology to separate the hardware of a wireless or satellite communications device from the software that shapes the radio signal over the air; allowing information to be transmitted and received between the devices (aka the waveform software). This not only transformed the form and function of the communications devices, but the very nature of military tactical mobile networking itself.

The hardware/software separation was largely facilitated by advances in programmable semiconductor chips with the ability to be programmed to behave differently, perform at unprecedented speeds, able to store large amounts of information while costing less every year. This concept of a software definable radio (SDR) was further facilitated by advances in standardizing the software communications architecture (SCA), enabling small blocks of specialized software to be assembled to deliver complex networking capabilities. These two technology improvements: better chips and better software design produced a highly capable tactical radio. These same technology advances are also enjoyed today by the telecommunications carrier and cellular industries and smart devices in virtually every sector. They unleashed four powerful enabling capabilities for the military:

1. Different devices of size, weight and shape can now be developed for widely different specialized purposes, yet be interoperatable while hosting the same software. The market continues to innovate to meet the needs of military planners and warfighters.
2. The waveform software itself is developed once but reused many times as developers produce new innovative physical forms that meet the military’s varied missions and different platforms. A wireless device on a ship can connect to a miniature device on an unmanned aircraft, which itself can be exchanging information with even smaller sensor devices or a dismounted Soldier’s handheld radio on the ground.
3. Not only are development costs reduced by reusing the software, but the recurring per-unit production costs are kept low by multi-vendor competitive market forces. The military now has options without being wedded to a specific vendor.
4. Lastly, but of paramount importance to the military’s modernization efforts: forces, teams, services, and even coalition countries, can all deploy tactical networking devices that suit their special needs, yet are assured of interoperability when they come together in joint exercises or live missions.

These developments led to the vision, depicted in Figure 1, of a battlefield consisting of multiple different physical devices based on mission and platform requirements, all employing the same “family of waveforms” to ensure interoperability; eliminating stove-piped vendor-dependent networks. The form factor and physical configuration of the radio device itself is no longer defined by the network, but by how it will be used in the mission. For a different mission, these same physical devices can be configured to host different waveforms; but still continue to interoperate. For the first time, mission planners can now configure networks that are mission-centric; not net-centric, device-centric or people- centric.

To realize this vision, the JTRS program incubated the technologies, concepts and processes that would implement and sustain this business model because industry would not venture into this ambitious new world on its own. JTRS was essentially embarking on overhauling how the military services define their communications requirements, translate them into acquisition strategies to buy what they need (not what is offered) and acquire equipment that meets their requirements in a stunningly different way.

To prove the business model, JTRS was structured as an umbrella organization that encompassed not one, but five Major Defense Acquisition Programs (ACAT-ID) shown in Figure 2. Four of them developed hardware architectures for the tactical SDRs. The fifth focused on developing the waveform software and net management software that could be hosted by these devices and any other devices developed for the future battlefield.

Collectively, these five programs under JTRS validated the JTRS enterprise business model (EBM), its processes and technologies. Once completed, the waveforms and net management software were available to be hosted on any variety of physical devices to meet platform, weight, battery power and size requirements. Military programs of record (POR) and independent vendors then requested to reuse this software on a recurring basis.

As a demonstration of the full range of SDR possibilities, JTRS chose to develop two categories of waveform software. The first category of software mimicked existing legacy radios currently deployed in the field, focusing on Single Channel Ground and Airborne Radio System (SINCGARS), Enhanced Position Location Reporting System (EPLRS), Ultra High Frequency Satellite Communications Demand Assigned Multiple Access (UHF SATCOM/DAMA) and HF radios.

The second category of software presented new and advanced capabilities to the U.S. military, focusing on the Wideband Networking Waveform (WNW), the Soldier Radio Waveform (SRW) and a new beyond-line-of-sight (BLOS) satellite waveform called the Mobile User Objective System (MUOS).

Why demonstrate two categories of software? It would have been simpler to prove an SDR can mimic SINCGARS, or to ignore the large inventory of legacy radios and simply point to the future networking features of WNW or MUOS. But central to the JTRS business model was, and still is, the concept of providing a technology development roadmap showing the military how its legacy capabilities coexist with its modernization efforts.

The JTRS model offers a powerful yet easy-to-understand transition roadmap. Whether speaking to an Army Brigade or smaller platoon, an Air Force squadron or entire wing, a U.S. Naval fleet or a smaller formation of naval assets, each software-defined communications network can evolve at the “speed-of-need.” For the first time U.S. operational forces can determine their budgets, timetables, capability gaps and priorities and chart their own course for modernizing their tactical networks. What they are assured of is the consistency of the devices’ interoperability across the tactical battlefield.

Examining Figure 1 closely reveals that the family of JTRS waveforms depicted extends the Defense Information Systems Network Global Information Grid to the very edge of the tactical battlefield. Information exchange and battlespace awareness can occur nearly instantly. Now, missions need to be planned in ways that exploit these new “info-weapons.” This requires equally innovative changes to training, mission planning and military doctrinal processes while preparation for and waging battle enter a new era.

Executing the Vision

Much of the JTRS vision and mission have been accomplished, including the following:

• The software depicted in Figure 1 for all the waveforms (legacy and new) now resides in the JTRS Information Repository (IR), along with design and test documentation, to assist vendors and program of record offices use of JTRS products in their preferred devices.
• The Handheld, Man-pack & Small Form Fit (HMS) program has delivered handheld radios (AN/PRC-154) hosting the new SRW waveform to the following U.S. Army units: 75th Ranger Regiment; 2nd Brigade, 1st Armored Division; 173rd Airborne Brigade Combat Team; and the 3rd and 4th Brigades, 10th Mountain Division. A manpack device (AN/PRC-155) hosting SRW, SINCGARS and SATCOM 181 is currently under limited production and testing. The same manpack device will also host DAMA and MUOS waveforms shortly.
• At their own cost, several industry vendors have “checked out” waveform software from the JTRS IR and are porting it to their radio form factors. So reuse of JTRS software has begun, with several vendors’ devices passing interoperability testing at government test facilities.
• JTRS has defined and validated detailed engineering processes for ensuring the affordability, reusability and interoperability of governmentowned software on multiple vendors’ devices. These processes were not developed overnight and were revised and improved as lessons were learned throughout the lifespan of JTRS programs. High impact components of these processes include:

• Access to an Information Repository that provides for each waveform: the source code; detailed design documentation; test specifications for how the waveform should be tested on any platform; and all previous test results conducted by government or vendor labs.
• Access to an Information Repository that provides for each waveform: the source code; detailed design documentation; test specifications for how the waveform should be tested on any platform; and all previous test results conducted by government or vendor labs.
• The establishment of standard JTRS application programming interfaces (APIs) and defined software communications architecture (SCA) standards that help vendors and developers port the waveform software to different hardware devices.
• JTRS collaboration with the DoD Joint Interoperability Test Command (JITC) to select and upgrade its labs and test fixtures enabling JITC to conduct independent testing of a vendor device hosting a JTRS waveform.
• Quarterly technical exchange meetings convened to foster collaboration among a “community of developers” who have a vested interest in their devices interoperating with each other, as well as training industry to step up and meet the rules of the new business model which includes affordable, interoperable and secure tactical devices that reuse software in which the government has invested significant funds.

• JTRS aligned its processes for improving, evolving and expanding its suite of waveforms to the Defense Department’s policies for future SDR development.

With much of its original mission completed, the JTRS program began a planned transition from an incubator to a maintainer and governing body for the reusable software it developed, completing the transition Sept. 30, 2012.

Having funded the body of work that defined unique hardware needs for these new advanced networking waveforms, it was time to exit the hardware business. The Joint Program Executive Office (JPEO) for JTRS transformed into an organization that facilitated the expansive, yet disciplined reuse of the software in its Information Repository; oversaw the evolution of these waveforms and expansion of the suite of waveforms, and certified security and interoperability compliance.

Figure 3 depicts the first stage of this transformation: All hardware program offices have now been transferred to the services that will deploy them first. Going forward, the military services can choose to port JTRS software to their own unique devices, reuse devices already deployed by other services or modify commercial off-the-shelf devices to suit their needs. Cost and mission objectives will dictate each decision, but interoperability would not be compromised.

Stage II of the transformation, shown in Figure 4, reorganized the remaining parts of JPEO JTRS to fulfill its future mission into the Joint Tactical Networking Center (JTNC) consisting of three components:

• Product Manager Joint Tactical Networks (JTN) to support the current software life cycle management and develop new waveforms as needed.
• Joint Reference Implementation Laboratory (JRIL) to assist programs of record and vendors in testing waveforms as they are ported or upgraded and assist DoD in evaluating ideas and technologies for new waveforms as they are developed by industry. JRIL leverages government test labs.
• A technical directorate that will serve two principal roles: (1) oversee the engineering processes that ensure the security and interoperability that DoD expects vendors and PORs to implement for the waveforms; and (2) interface to the science and technology communities (inside and outside the DoD) to bring in new advanced capabilities to the current family of waveforms.

Although JTNC was placed administratively under the U.S. Army, DoD’s acquisition decision memorandum directed that all service branches leverage JTNC waveforms. With this new focus, JTNC has become the gearbox that drives the execution of the military’s acquisition for advanced tactical networks for modern warfare. These networks will host secure interoperable software on whatever physical devices serve their missions.

Navy Relevance

Many lessons were learned in executing the JTRS vision. While JTRS launched technology innovations and next generation communications capabilities to the military, it used equally innovative acquisition strategies, business models, test and evaluation processes, and test, modeling and simulation tools that virtually did not exist anywhere in network labs around the world. Valuable lessons were learned in all of these areas. How does the Navy leverage these capabilities? A closer examination of Figure 1 offers a clue.

The Navy’s study of littoral combat refers to operations in and around the littoral zone, within close distance of shore, including surveillance, mine-clearing and support for landing operations and other types of combat shifting from water to ground and back. Interoperability must extend seamlessly between ground, air and sea platforms.

Today, the U.S. Navy is building on its adoption of the software-defined MIDS radio shown in Figure 5. This radio has already incurred thousands of hours of flight testing, hosting the Link 16 waveform. Its four-channel radio can carry any mix of legacy or networking JTNC waveforms. Hosting a tactical data link (TDL) allows naval airborne assets to communicate with ground forces. Hosting the new MUOS satellite waveform allows the device to provide BLOS reach-back to tactical Link 16 platforms and to ground forces.

Equally, the Navy is taking advantage of another JTRS-incubated program: the AMF radio, shown in Figure 6. This two-channel radio is a smaller form factor than MIDS, for smaller airborne platforms.

Hosting MUOS and any other ground or airborne waveform, this device can be another component for the Navy’s new role in littoral warfare. Whether interoperability is sought between the Navy’s air and sea platforms, across the services or with coalition and friendly forces, hosting the same family of waveforms on any radio device that fits the Navy’s mission allows it to participate up close and personal with mission partners.

Program Key Characteristics

Interoperability is defined as “the ability of diverse systems and organizations to work together.” Ultimately, this is a people challenge, not a device or technology challenge. JTNC has developed detailed processes for testing and verifying interoperability before a new device is inserted into the field.

Without interoperability, the business model breaks down and we risk regressing back into the costly and fragmented networking morass that DoD is resolved to fix.

Affordability is achieved by being able to reuse the same family of waveforms so that DoD’s return on investment increases as more devices host the software. JTNC has developed APIs and SCA guidelines and test tools to facilitate reuse and maximize return on investment.

Security is safeguarded by protecting the membership of the family of waveforms. JTNC’s waveforms are certified by the National Security Agency for each and every platform that hosts them, which guarantees the trustworthiness of the network fabric across the battlefield.

Interoperability, affordability and security are designed into each waveform. Each waveform encompasses a clear architecture, disciplined configuration management process and vigorous verification and validation testing to ensure compliance and certification before radio devices are launched into the battlefield.

Some parties resist assigning such a role to JTNC, viewing it as too much consolidation of authority into one organization. This argument misses the point. With the Defense Department revamping its policies for development of radio software and overhauling its acquisition practices to buy smarter, the legacy groundwork laid by JTRS should be exploited to get the maximum investment return on scarce defense dollars.

JTNC stands ready to sustain and further innovate the JTRS-developed, fully capable, secure and interoperable family of waveforms.

FOR MORE INFORMATION

The Joint Tactical Networking Center provides affordable, interoperable and secure tactical wireless networking in support of Service, multi-Service/Joint and coalition forces: www.jtnc.mil

S. S. Kamal is the chief scientist for engineering at SAIC International.

John T. Armantrout is the technical director of the Joint Tactical Networking Center.