Roadblocks ahead for joint tactical radio: among the challenges are aircraft integration costs and antenna technology.

One of the Pentagon's largest-ever military communications programs is getting off on a slow start, hindered by the sheer scope of the project and the inherent difficulties in consolidating up to 25 families of radios into one.

Under the Joint Tactical Radio System, the Defense Department plans to field a single family of software-programmable radios, to replace more than 750,000 devices now used by the military services.

Software-defined radio is viewed as the holy grail of military communications, a technology that promises both efficiency and seamless interoperability among the U.S. services and foreign allies.

A software-defined radio box functions much like a PC. The software radio applications, called waveforms, are based on common standards, but designed to meet each service's specific needs. The basic operating software is the SCA (Software Communications Architecture), the equivalent of Windows on a PC.

The first segment of the JTRS program, called Cluster 1, got under way more than a year ago, with the selection of a Boeing-led contractor team to produce up to 106,000 JTRS boxes for Army aircraft, ground vehicles and Air Force forward air controllers.

Under Cluster 2, the Defense Department is developing handheld radios for the U.S. Special Operations Command. The contractor, Thales Communications, is adapting SOCOM's multi-band intra-team military radio, known as MBITR, to make it SCA-compliant.

Yet to be awarded are contracts for Cluster 3 (maritime radios), Cluster 4 (radios for all Navy and Air Force aircraft) and Cluster 5 (portable radios for dismounted troops).

The JTRS program office also is considering a Cluster 6 version, for high data rate transmission (up to 200 megabits per second). Additionally, the JPO is evaluating bids for a law-enforcement version of JTRS.

The entire JTRS program is estimated to be worth at least $3 billion in U.S. military contracts. Industry officials speculate there is potential for another $3 billion in international sales.

Experts generally agree that the JTRS program is both technologically demanding and difficult to implement at an affordable cost, given the diversity of requirements. The program office already is facing significant schedule slips and cost overruns in Cluster 1, sources said. Driving the cost growth are larger-than-expected price tags for installing the radios aboard older aircraft and ground vehicles.

The U.S. Air Force, meanwhile, is struggling to figure out how to fit the development and procurement of JTRS into its overall aircraft modernization plans. The Air Force plans to spend $1.5 billion in the next l0 years on Cluster 4.

The JTRS program has been a "really hard sell" in the Air Force, said Col. Charles Whitehurst, a requirements officer at the Air Combat Command.

With 124 different types of radios, the Air Force could stand to save lots of money by adopting a single family of JTRS radios, Whitehurst said. The AWACS warning and control radar aircraft, for example, would go from 30 radios (1,500 pounds) to four radios (875 pounds).

The problem is that most senior officers in the service are not convinced that the benefits would outweigh the cost of retrofitting hundreds of aircraft, especially when JTRS dollars will be competing with more pressing funding priorities.

"Users wanted GATM (Global Air Traffic Management) and Link 16, but not JTRS," Whitehurst told a conference of the Institute for Defense and Government Advancement, in Alexandria, Va.

JTRS introduces a whole new culture with which the services may not yet be comfortable, he noted. "Nobody talks in waveforms. They talk in frequencies--VHF, HF, Link 16, GATM."

A typical reaction to JTRS from military commanders is, "'Why should I care?'"

The cost of modifying every aircraft to fit new radios worries the Air Force, said Whitehurst. "It's a whole lot different problem than ground vehicles." The paperwork alone would be taxing. ACC estimated that approximately 314 officers will need to approve the "migration plan" to JTRS for each type of aircraft in the Air Force.

Service officials, however, will begin to embrace JTRS once they understand the long-term implications of the technology, Whitehurst said. With JTRS, "if you want to change the radio in the future, all you have to do is hook up the laptop and update the waveform."

Another concern for both the Air Force and the Navy is the JTRS development schedule. The new radios would not be fielded until at least 2008, a goal viewed by many as too optimistic. In the meantime, the services expect in the near future to upgrade aircraft with MIDS (multifunction information distribution system) radios equipped with the Link 16 data-link. According to Rear Adm. Mark P. Fitzgerald, director of air warfare, "MIDS is probably the single biggest thing that is going to drive the next revolution" in air combat, he told a conference of the National Training Systems Association.

The services today operate more than 2,000 MIDS radios. The plan is to buy 4,000 more, none of which would be SCA-compliant.

Because software-defined radio, or SDR, is the mandatory standard for every Defense Department program, any upgrade project that involves non-SDR radios must receive a special waiver from the Pentagon's chief information officer.

"Between now and 2008, we are going to be processing a beck of a lot of waiver requests," said Whitehurst.

Pentagon CIO official Frank Criste explained that waiver requests are submitted through tire service chain of command. They are vetted by representatives of the CIO office, the Joint Staff, the JTRS Joint Program Office and the military services. Approximately 50 waivers have been approved this year, according to Criste.

The director of the JTRS Joint Program Office, Air Force Col. Steven MacLaird, also expressed concern about integration costs. A MIDS radio runs about $225,000, but it costs an additional $450,000 to install it on an F-16 fighter.

Neither the Air Force nor the Navy wants to pay nearly a million dollars per airplane to install JTRS only a few years after they have spent a comparable sum on MIDS, industry sources said.

For that reason, the JTRS Cluster 4 is likely to be designed so it takes up the same space and weight that already has been allocated on airplanes for the MIDS radio.

A similar problem applies to the widely used military radio, the AN/ARC-210. The Air Force and the Navy want the JTRS radios to fit in the space already assigned to the ARC-210 radios aboard aircraft. The ARC-210 is a multimode communications system for voice and data that operates in line-of-sight or satellite modes.

Adding to the complexity of Cluster 4 is the requirement to accommodate 65 different types of aircraft, including unmanned drones, Coast Guard and civilian platforms.

The program may not meet its ambitious schedule, given the variety of platforms that must be dealt with, said Dennis W. Marsicano, lead engineer for airborne joint tactical radio at the Mitre Corp.

"We are under a lot of schedule pressure from the users," he said at the IDGA conference. "In some cases, we won't be able to get there in the time required."

Cluster 4 contractors, Marsicano said, will be asked to develop a joint tactical radio that "form fits" the space and weight of the MIDS and ARC-210 radios.

One industry source noted that the Air Force cannot afford any major delays in the JTRS program, because it needs to integrate it with its new multi-sensor command and control aircraft, the MC2A.

"MC2A is driving Cluster 4 to come online by 2006," he said. "The Air Force cannot afford to build the airplane without JTRS."

The Navy wants a JTRS surrogate now, while it's upgrading its airplanes, instead of having to upgrade them again in 2006 or 2008, he added.

Another industry expert questioned the wisdom of adapting the MIDS and ARC-210 radios for Cluster 4, instead of developing a new box.

"The MIDS mafia is pushing for that," the expert said. "It's all about getting stuff in the near term, to match up with aircraft upgrades already scheduled. ... I don't think that is the adequate solution."

The Naval Air Systems Command, particularly, does not want to "screw around with the interfaces on the F/A-18 for the ARC-210," the source said. "I think that is a pretty myopic view of the world."

This incremental approach defeats the purpose of having a JTRS program, he said. "If you are not willing to take a giant step forward, why are you doing something as dramatic as JTRS anyway? If you are just playing the compliance game, it's kind of silly."

Expanding JTRS

The entire JTRS program includes 33 radio waveforms that operate in the frequency range between 2-Megahertz and 2-Gigahertz. Of the 33, 32 are applications that have been in use for many years, such as the Army's SINCGARS and the Air Force Have Quick. The only new application to be developed specifically for JTRS is the wideband networking waveform.

In June, meanwhile, the Pentagon CIO office moved to expand the scope of the JTRS program. CIO John P. Stenbit amended the software-radio policy by mandating that all radio systems operating above the 2-Gigahertz frequency, up to 55-Gigahertz, be JTRS-compliant. This policy primarily affects space-based communications systems.

MacLaird said the new policy has significant implications for the program, but it's premature to predict how specific projects will be affected.

The JPO now has more pressing matters to solve, such as whether the JTRS radios can deliver what they promise.

So far, it is nor yet certain that these radios will be able to perform to military standards. One specific issue of concern is "quality of service," said MacLaird. Software radios, like PCs, may require occasional rebooting, especially when changing waveforms. The process of switching bands now takes about 13 seconds in a JTRS radio, while it only takes conventional radio operators two seconds to switch frequencies. To call up a different waveform could take up to 45 seconds.

Gaps in quality of service are not acceptable in military operations, he said. "I cannot stand to be shot at and get the communications 80 percent of the time."

The time it takes to reboot a software radio poses a "big problem that we are continuing to address," said Byron Tarver, software-defined radio engineering manager at General Dynamics Decision Systems.

Another technical hurdle are the antennas. Even though multiple radio applications can be consolidated in a single box, a JTRS radio still would have multiple antennas, adding to the load of the dismounted soldier.

"There is today no single antenna that can provide connectivity for all these waveforms," said Gary Martin, deputy program manager for Army tactical radio communications systems. "Cluster 1 still will have multiple antennas," he said.

The Army is concerned about how antennas will fit on unmanned aircraft, which are being designed to serve as communications relays. "You don't want a porcupine sticking out one of these vehicles," Martin said. Additionally, "as you start putting multiple antennas on these vehicles, co-site interference becomes a problem."

As more military users opt for satellite communications, more antennas are needed, he added. "SATCOM will play a more significant role in the Army. ... When you are moving in mountainous terrain, SATCOM is a far better choice than line-of-sight" systems.

"When you talk about antennas, you get into physics," Tarver said. The wavelength of a transmission is directly proportional to the size of the antenna. "It is a limiting technology," he said. The problem is exacerbated in handheld radios. "You can't afford to put either a large antenna or a multiplicity of antennas. In a vehicle, I can put six antennas."

Airborne antennas also fall short of what the military wants, Martin said. "It's really an art [to design antennas]. An awful lot of work needs to be done."

What keeps JTRS engineers awake at night is the requirement that manpack (man-portable) radios operate 15 waveforms. "We are going to have one guy with the radio and two guys following with the antennas," Martin said.

Among the most technically demanding pieces of the JTRS program is the wideband networking waveform, designed to transfer data at 5-8 megabits per second. By comparison, most tactical networks today transmit 16 kilobits per second. The work is funded under JTRS Cluster 1.

The WNW can he described as a "smart waveform," according to one industry source. It is supposed to automatically hand off information from one mobile network to another. "It's a tough requirement," the source said.

Martin said that the WNW would be scalable up to 1,600 nodes per network, to support an Army division. "Over time, whether that is the right number or not depends on the Army structure," he said.

The most difficult job in the WNW project is the ground-to-air integration, Martin said.

Navy Capt. Sherman Metcalf, program manager for JTRS Cluster 3, said that WNW, scheduled to be completed by 2006, will allow the Navy to set up networks among ships, airplanes and shore sites, "or whatever is in line of sight." Cluster 3 radios will go aboard submarines, surface ships and on shore installations, and will operate 30 waveforms.

Tarver noted that the wideband networking technology already is mature in the commercial sector. But commercial systems, he cautioned, cannot meet JTRS requirements.

"You can get more capability with a commercial 802.11 standard," Tarver said. "But the WNW is targeted specifically to get high data rate in a common standard across the services, so you solve the interoperability problem ... and the unique networking" features the military wants.

Batteries also could become a headache for JTRS users, said Gus Zader, project manager for JTRS Cluster 2 at the Special Operations Command. The current battery in the MBITR radio lasts 12 hours. But the goal for JTRS is 24 hours.

Zader anticipates that software upgrades for JTRS will be tough to manage, given that each contractor follows its own unique software configuration management. "Keeping up with the software upgrades and tracking down all the radios to get them upgraded" could become a nightmare, he said. "With most SOF deployed, keeping track of the configuration is a real challenge."

Under Cluster 5, the JPO plans to field three types of soldier radios by 2008: a manpack, a handheld and a so-called "embedded" radio for the Land Warrior system and for robotic vehicles, said Martin. These are "radios that have connectivity to the network but are not traditional radios."

The Army does not provide adequate communications to dismounted troops, he explained. "Once they get out of their vehicles, they are not plugged in."

Commercial Radios

The Defense Department, meanwhile, has been buying software programmable radios for non-combat applications.

The Air Force, for example, recently purchased 2,500 software-based land mobile commercial radios for eight Air Combat Command bases.

The $7.8 million contract eventually will add radios for all 22 ACC bases, said Jim Ridgell, vice president of federal business at EF Johnson, the company that won the contract.

The ACC radios must comply with the Project 25 standards, making them interoperable with local and state first responders and homeland security agencies.

Since 9/11, said Ridgell, "there is a need fur all Defense Department bases to become more interoperable with local counties and municipalities surrounding the bases."

EF Johnson is considering partnering with a defense contractor for future JTRS competitions. The military radio business, however, is too risky for a small commercial company such as EF Johnson, said Ridgell. The three-to-five year development cycles in military programs require significant corporate investment, which small firms cannot afford. "As a small company, we are interested, but there is no near-term revenue," said Ridgell. "Other agencies we support offer a more ready return on investment."