The next-generation tactical-communications technology—the
Joint Tactical Radio System—will provide conventional military
units with capabilities that typically are associated with special
Currently in the early states of development, JTRS also is expected
to give U.S. special operations forces improved software-defined
radios, readily tailored to their mission requirements.
In their secret missions, special operations forces (SOF) rely
on secure, reliable communications to interact with their own joint-service
units, conventional U.S. forces and international allies.
Today, discrete radios carry voice, digital data and video at high,
very high and ultra-high frequencies (HF, VHF, and UHF)—using
encrypted and jam-resistant waveforms. They enable Army Rangers
to talk to Air Force gunship teams and Navy SEALs to “burst”
data to distant joint-service commanders, with or without satellite
Special operations forces participated in setting the requirements
for the development of the JTRS operational requirements document,
released in 1998. SOF requirements also will be incorporated in
each new “cluster” of JTRS radios.
The software-defined JTRS was designed to replace single-function
legacy radios and “stovepipe” communications with multi-mode
(simultaneous data, voice, and video) sets that network air, ground
and maritime users. The initial versions of the new common radios
are to span the entire frequency spectrum from 2 MHz to 2 GHz and
effectively put several radios in a single box.
The special operations community, meanwhile, already operates software-defined
radios. In recent years, the U.S. Special Operations Command (SOCOM)
has purchased the AN/PSC-5 UHF/VHF Multi-Band Multi-Mission Radio
(MMBMR). The manufacturer, the Raytheon Co., has delivered both
man-pack and vehicular versions. It replaces several-single band
radios, sending voice, data and imagery over line-of-sight or SATCOM/DAMA
(Satellite/Demand Assigned Multiple Access) networks at frequencies
from 30 to 512 MHz. The PSC-5 can use SINCGARS (Single Channel Ground
and Airborne Radio System) and Have Quick I and II waveforms to
defeat enemy jamming. An enhanced encryption key management system
provides COMSEC (Communications Security) with up to 250 keys. Plug-in
modules expand the capabilities of the radio as needed.
SOF units also have acquired the software-based AN/PRC-117F(C)
and AN/PRC-150(C) radios from Harris RF Communications, to provide
short-range and long-range capabilities. Both carry encrypted voice
and data communications, and both can display and transmit precision
location beamed by external GPS (Global Positioning Satellite) receivers.
SOF units use these two radio systems during reconnaissance and
other operations in hostile territory to transmit information in
short bursts that prevent interception and location. An automatic
repeat request confirms the burst was received without errors. To
ensure secure communications, both radios also incorporate U.S.
Type 1 (mandated by the National Security Agency) voice and data
encryption capabilities, eliminating external encryption devices.
The PRC-117F is the VHF/UHF and UHF SATCOM (30 to 512 MHz) man-pack
radio currently used by Air Force tactical air controllers and others
to communicate with ground and air units. Digital data-handling
capacity is 64 kilobits per second, over line-of-sight channels.
To maintain transmission security even under enemy jamming, the
radio contains Army VHF SINCGARS and Air Force UHF Have Quick frequency-hopping
waveforms in software. The radio has a built-in satellite modem
with communications standards also configured by software.
The PRC-150 is an HF and low-band VHF (1.62 to 60 MHZ) radio for
longer-range communications. When satellite lines of sight are unavailable,
HF radios are used to bounce transmissions off the ionosphere. Unlike
its special-operations HF radio predecessor, the PRC-150 provides
automatic link establishment to find the best frequency based on
changing ambient conditions. HF digital data transmission rates
are up to 9,600 bits per second. Also unlike previous radios used
by special operations forces, the PRC-150 is Type 1 encrypted for
secure message traffic.
Earlier radios required hardware upgrades in order to add new features.
But both the AN/PRC-117F and AN/PRC-150 can be upgraded purely through
software changes. Updates in VHF SINCGARS waveforms or SATCOM protocols,
for example, can be downloaded to the -117F radio through a computer
Joint Tactical Radios, additionally, will provide embedded position-location
reporting capabilities to enhance situational awareness. The objective
sets will ultimately incorporate satellite-communication capability.
And unlike today’s purpose-built radios, the JTRS will have
an open architecture so it can be upgraded in the field by installing
applications from a software library maintained by the JTRS joint
“Think of it as a PC,” explains Army Col. Michael Cox,
of the JTRS program office. “In terms of data throughputs,
it will have same capabilities as legacy radios, plus ones not developed
yet.” While current radios are largely proprietary packages
of hardware and software, JTRS separates government-owned waveforms
from modular hardware.
Radios will be delivered with waveforms and other applications
installed. Hardware makers will integrate government-furnished or
licensed software. Once the radios are in service, the government,
the hardware manufacturer, or a third party may install new plug-and-play
The JTRS terminals are expected to take software updates transmitted
on secure networks. To comply with the requirement to have an open
architecture, JTRS hardware and software will conform to a single
Software Communications Architecture now under development by an
industry organization called the Modular Software Radio Consortium.
JTRS is expected to result in the production of up to 260,000 radios,
100,000 of which will be in the Cluster 1 procurement. The JTRS
family of radios will include different boxes clustered to fit the
ground, air and maritime domains of all the services. Hardware will
adhere to current commercial standards and standard interfaces will
accommodate different waveforms without redesigning the waveform
or the radio. Plans call for the same basic handheld ground radio
for conventional Army, Navy, Marine and Air Force units and special
There are several SOF-unique requirements. Not all handheld radios,
for example, need to meet SEAL requirements to withstand submersion
600 feet below the ocean surface.
The first JTRS cluster includes ground vehicular radios for the
Army and Marine Corps, radios for Army helicopters, and sets for
Air Force tactical air control parties. An early operational assessment
is scheduled for 2004. Cluster 2 handheld radios—designed
for joint-service and SOCOM requirements—are scheduled to
begin development in 2004 or 2005.
SOCOM already has launched JTRS-oriented projects, such as vehicle
adapters and information networks to run commercial application
With common radios, a broader range of platforms will be compatible
with special operations forces. With today’s dedicated radios,
submarines, for example, must be specially equipped with VHF sets
to communicate with Navy SEALs on specific missions.
The U.S. Navy already is investing in software-based radio technology,
under the Digital Modular Radio program. Last April, the Navy Space
and Naval Warfare System Command (SPAWAR) awarded a second production
order of $39.6 million to General Dynamics Decision Systems, bringing
the total contract value to $95.6 million.
The DMR is a software-controlled and re-configurable digital system
that provides interoperability among diverse legacy radios.
The company’s wireless technology is being used under a separate
contract with the JTRS Joint Program Office to validate the Software
Communications Architecture (SCA).
The DMR employs commercial-standard processors and software, and
will enable the Navy to train its radio operators on one platform
and replace numerous, previously incompatible systems with a single
system which communicates seamlessly with different armed services
as well as the U. S. Coast Guard and NATO allies.
To protect data from intruders, the DMR has the Advanced INFOSEC
Machine (AIM), which received Type 1 Certification from the National
Security Agency. It simultaneously operates on multiple channels
using different algorithms, enabling it to potentially replace many
standard encryption functions with a single device.
General Dynamics is a member of the JTRS Futara Team, which is
led by the Raytheon Co. The team also includes SAIC, TRW and ITT
The Futara team will compete for the Cluster 1 award against rival
Boeing Space & Communications. Boeing’s partners are BAE
Systems, Harris RF Communications and Rockwell Collins.
The JTRS program could generate up to $1 billion in sales for U.S.
companies, without including foreign sales to allied nations.
One of the most technically challenging requirements in the JTRS
program is the development of a new wideband waveform, which will
enable thousands of users to transmit and receive heavy volumes
of data, including graphics, voice and video-teleconferencing.
In 1999, Raytheon received a contract to define an architecture
for the new radio. The company demonstrated VHF-FM, VHF-AM, VHF-FM
public service, VHF air traffic control, Have Quick I & II,
and MIL-STD SATCOM waveforms in early 2001. ITT, Rockwell Collins,
and BAE demonstrated SINCGARS SIP, wideband data, HF-Automatic Link
Establishment (ALE), VHF-FM, and VHF-FM waveforms. The ALE waveform
was demonstrated in a Raytheon prototype radio using Rockwell-Collins
software. During the architecture validation tests, JTRS prototype
radios also worked with legacy ARC-164, ARC-222, VICS, VRC-100,
and SINCGARS radios.