Wideband Vistas for the Disadvantaged
Written by Adam Baddeley
Soldiers Radio Waveform allows critical,
real-time voice data and video to be routed
seamlessly to the personnel who need it.
The SRW provides data throughput that at the time of Desert Storm would have been limited only to formation-level commanders. The waveform combines this with advanced networking that allows critical, real-time voice data and video to be routed seamlessly around terrain and inside buildings to the personnel who need it.
The SRW offers massive quantitative and qualitative advances over its predecessor— ITT’s SINCGARS, which today is the waveform of choice for dismounted operations. “The SINCGARS environment gives you low Kbps, the SRW gives you low hundreds of Kbps—basically a two orders of magnitude improvement in throughput,” explained Larry Williams, technical director for ITT Communication Systems.
That throughput power is one pillar of the SRW’s potential. The other is its package of complex ad hoc networking algorithms. In contrast, traditional networks have been very planning intensive and largely fixed.
“Once you design and set up the network, it won’t change throughout the operation,” Williams said. “The SRW environment manages the network itself in terms of connectivity, and scalability is totally dynamic. There are planning features, but once you have the initial IP addresses loaded, you don’t touch any of the routing or connectivity decisions, because the network dynamically figures those out and adjusts them as conditions change.”
The impetus for the SRW dates back to 1994 as a response to the “Blackhawk down” incident in Mogadishu, Somalia, in which the shortcomings of existing communications in overcoming complex urban terrain were shown to have seriously hampered operations. This prompted an entire series of studies at the Secretary of Defense level, examining requirements for communications and navigation for small dismounted units.
Following these studies, the Defense Advanced Research Project Agency (DARPA) initiated the Small Unit Operations- Situational Awareness System (SUO-SAS) program. It selected ITT as its partner, following a series of competitive down-selects, to demonstrate a number of critical capabilities. These included a communication waveform capability that could adapt and communicate across a wide diversity of terrain—in the open, in the jungle or in urban “canyons.”
The second objective was a lightweight command and control capability that would allow everyone to be aware of both friendly and enemy actions. Thirdly, it was to be able to assist platforms to know where they were, solving the GPS “dropout” problem when users went into buildings or under tree canopies.
The capstone event for SUO-SAS was a demonstration of all three capabilities at Fort Benning, Ga., in 2002, which Williams described as the defining moment for SUO-SAS.
“It was raining, cold and no one wanted to be out, but even with all the problems, the systems still worked,” he recalled. “At one point they had a helicopter that was going to rise above the horizon. When the helicopter broke the horizon, all of a sudden, all the disparate small unit groups that were scattered across Fort Benning could simultaneously see each other. It demonstrated the power of this self-forming, self-healing networking concept.”
INTEGRATED ENVIRONMENT
As a result of that demonstration, the Army’s Communications-Electronics Research, Development and Engineering Center (CERDEC), after being involved in DARPA’s work for some time, decided to take responsibility for the work, renaming it the Soldier-Level Integrated Communications Environment (SLICE) program.
The work under DARPA demonstrated fundamental technologies, such as overcoming multi-path interference and structuring dynamic networking and scalability into the network. Under SLICE, CERDEC extended those concepts to address a wide range of operational considerations, including very long battery life, multiple video feeds and reduced frequency availability.
A key change in the program was the expansion to connect soldiers with other types of weapons and sensing systems. Each had specific requirements—unattended ground sensors (UGS) designed to operate in the field for up to 60 days, for example, and non-line-of-sight (NLOS) missiles and UAV, which operate at high speed in the air.
“We created waveform variations, allowing the same basic waveform to support all of these different domains so that an individual soldier could fit into a sensor network or, by a press of a button, could be part of the NLOS missile systems network,” Williams said.
In 2006, the Program Executive Office Joint Tactical Radio System (JTRS) formally added the SRW to the JTRS operational requirements document (ORD), listing SRW as a requirement in both handheld, manpack, small form fit (HMS) and ground mobile radio (GMR). This was followed by a further competitive selection for SRW development, which ITT again won.
Starting in 2006, ITT began supporting CERDEC’s annual C4ISR On the Move demonstrations, which are used to validate operational architectures. Also included were the Air Assault Expeditionary Force, now known as Army Expeditionary Warrior Experiments, activities at Fort Benning, designed to fine-tune and validate future operational tactics and procedures.
These looked at company-level deployments, Williams noted. “That may be several hundred vehicles, troops and UAVs, all integrated together. You might deploy sensors along the way for perimeter control, or UAVs for either comms relay or sensor collection, all using the SRW waveform. Two years ago we had nearly 100 nodes. The limitation is not the waveform or a radio, the limitation has always been the number of platforms or people the Army could put together for the experiment.”
ITT has provided the Army with more than 300 radios to support SRW experimentation, including Future Combat System (FCS) development. Asked about a notional limit for a network, Williams demurred, commenting, “It’s designed to be highly scalable.”
ITT delivered the final ORD-compliant version of the waveform, known as SRW 1.0C, to the JTRS Joint Program Executive Office in January, following formal qualification tests that prove that the feature set and performance of the waveforms meet the JPEO’s requirements.
“That was the delivery of the specified waveform code to fulfill the soldier, sensor and NLOS domain requirements of SRW 1.0C that will be fielded with JTRS HMS, GMR and Airborne Maritime Fixed,” said Dave Prater, vice president, JTRS business area, for ITT CS. “Previously, we have ported an interim release to assist HMS and GMR programs to make sure that their operating environment and hardware will be able to support it appropriately.”
Prater said that relative to other waveform developments, SLICE/SRW has taken very little time to complete. “It also represents a successful transition from a DARPA/ hard-science effort to a military acquisition. Those don’t happen that frequently.”
SRW 1.0C will now be put in the JTRS Information Repository. “Think of it as a library,” Williams suggested. “From there, various programs have the authority to take the waveform and instantiate it on their own platforms.”
Because of the complexity of the waveforms, ITT is working directly with the HMS and GMR programs on integrating SRW.
Additional capabilities will be added over time, as developers look for ways to improve throughput and operations in unique environments. These include teleoperation features for use with UGVs that are currently being studied as a software upgrade to the waveform. RF-based geolocation, part of the concept from the days of SUO-SAS, is another capability that will be added in the near future and is being addressed by ITT and CERDEC within the context of radio-based combat ID concepts.
RIFLEMAN RADIO
The Rifleman Radio, developed by General Dynamics C4 Systems and Thales under the JTRS HMS program, relies on the SRW. It will be the first true, netted voice radio with National Security Agency (NSA) certification to be fielded to troops.
Formerly called SSF-C(v)1, the Rifleman Radio recently received its formal nomenclature: the AN/PRC-154. The radio passed its pre-LUT (limited user test) at Fort Monmouth, N.J., in February, comprising laboratory and dynamic outside testing, and was scheduled to undertake its LUT in April.
“The biggest new capability the Rifleman Radio gives troops is networked voice, because all they have right now is pushtalk line of sight,” said Joe Miller, JTRS director for General Dynamics C4 Systems. “This extends the network, giving coverage in wadis, caves and urban environments where they don’t have it today.” The radio also supports packet data for situational awareness.
Performance at the February test was significant, Miller explained. “The minimum entry criteria for us for the LUT were 30 nodes, and we comfortably exceeded that.”
The waveform’s ad hoc networking also posed some interesting challenges for Army testers, Miller continued. “At Fort Monmouth, they did some range testing and tried to ‘break’ the network. But they couldn’t get far enough away on post to actually break the network connection.”
The PRC-154 uses Type 2 encryption, and so is not a crypto-controlled item. The radio has gone through NSA’s information assurance technical interchange meeting, which is the equivalent to a critical design review. In the fall, it will begin final testing, which is required before low rate initial production (LRIP) radios can be shipped.
The radio will be produced by General Dynamics C4 Systems and Thales Communications. A Milestone C decision is scheduled for September depending on completion of a test report from LUT. The radio would be fielded six months after an LRIP decision.
As part of HMS, General Dynamics is also supporting testing of SRW-based networks for UGS, providing radios to Textron and Boeing’s System Integration Lab. “Our network test environment contains SFF-A sensor radios and the PRC-154, which exchange information over SRW. We have also modified the waveform for an Army training application, with internal funding, and have tested it in excess of 100 nodes for PEO STRI,” said Miller.
The General Dynamics C4 business unit is also investing in security development that potentially is applicable to the SRW. The waveform is currently not High Assurance Internet Protocol Encryptorcompliant (HAIPE) and so doesn’t include discovery services associated with the Type 1 encryption standard. “On our own investment we have integrated standard HAIPE with SRW and have done some testing with that,” Miller noted. “We are also working on discovery services with NSA.”
DoD officials are looking to migrate all the new networking waveforms to a standard HAIPE-based architecture, although there is no specific timeline for the migration. The first waveform to implement those standard, HAIPE-based services is the Mobile User Objective System, a UHF MILSATCOM waveform developed by General Dynamics.
General Dynamics has already shipped HAIPE-equipped HMS radios to the FCS community, where they are doing network testing at the Network Analysis Integration Lab at Fort Monmouth, evaluating the performance of those radios with HAIPE in the network.
Prater cited ITT’s work with the SRW using its Wearable Soldier Radio Terminal, which has been running for three years, initially using the non-fieldable version of the waveform, SRW 0.5.
“We are running full SRW 1.0C on actual handheld hardware today,” he said. “We also have SRW 1.0C going into our Sidehat units, and we think those are still a very attractive and affordable way to get the networking capability onto a lot of vehicles that already have a brand-new SINCGARS radio sitting on them.”
WIDEBAND NETWORKING
Harris RF Communications successfully ported SRW 0.5 to its independently developed Falcon III AN/PRC-117G multiband manpack and RF300S Secure Personal Radio in 2008.
“We have proven to customers that SRW can be ported to our platforms including our JTRS-approved AN/PRC-117G. We have provided numerous customers with demonstrations and now are just waiting for SRW to be finalized, at which time we will incorporate the final version,” said Steve Marschilok, vice president and general manager for DoD business.
Harris has ported significant portions of SRW V1.0C, including network formation, voice and data operation, and has demonstrated these capabilities to the JPEO Network Enterprise Domain. “Our V1.0C porting activities have likewise not run into any difficulties,” Marschilok said. “This shows that the JPEO’s software model— ease in waveform porting to JTRS-approved and -certified radios—works.”
A new focus is porting the Wideband Networking Waveform (WNW), which has been obtained from the JPEO. “We’re working toward getting WNW to the same stage we have with SRW and demonstrating it to customers,” said Marschilok. “That, too, is going well. We have already provided some limited demonstrations to key customers of WNW capabilities in the AN/PRC-117G. The JPEO is very helpful to us and treats us like a program of record from that perspective. We have open access to the JTRS waveform library, which is consistent with the JPEO’s enterprise business model.”
Adding a wideband capability to support SRW in the narrowband handheld AN/PRC- 152 is on the road map but not an immediate priority for customers, Marschilok said. Outside both the SRW and WNW is Harris’ own wideband waveform—the Adaptive Networking Wideband Waveform (ANW2.) This was originally developed as a surrogate to allow customers to use the unique wideband capability in the AN/PRC-117G while the SRW and WNW waveforms were under development.
ANW2 is being shipped with the AN/ PRC-117G, which is now in operational service and has been fielded by all branches of DoD, making the ANW2 unique. “It is the only wideband waveform in a JTRSapproved, NSA Type-1 certified radio being fielded today. If DoD wants a fielded waveform in a secret/top secret, wideband JTRSapproved tactical radio right now, running high-speed applications like streaming video and able to hook up to the SIPRnet, then they have one place to go,” said Marschilok. “That is the 117G.
“We have significant customer interest in ANW2 becoming a DoD waveform,” he continued. “As our customers field increasing numbers of AN/PRC-117Gs, they are finding more and more interesting applications for it. It is looking more likely that some day it will become a DoD waveform. We don’t see it as a competitor to the SRW and WNW. If customers find applications for it in the field, then it can live and coexist with the other waveforms.”
In terms of capability, the ANW2 complements SRW and provides many of the capabilities of WNW, Marschilok said. “ANW2 has ranges that the SRW is not able to attain. It is not as ‘big’ as WNW is planned to be. We imagine ANW2 supporting subnetwork sizes of from tens to perhaps 100 nodes, but certainly not hundreds of nodes. Customers will create larger networks by linking the sub-networks together.”
GROUND MOBILE RADIO
In addition to the SRW, the JTRS program will also make use of a second wideband waveform, the WNW, which is being developed as part of the Boeing-led GMR program. The WNW is an integral part, not only of GMR, but also of the radio itself.
“WNW is lock-stepped with the GMR program,” said Boeing JTRS GMR Program Manager Ralph Moslener. “WNW is literally being developed on the target platform, which is the GMR.”
In February, Boeing delivered the first GMR engineering development model (EDM) radios ready for this summer’s FCS spinout LUT at Fort Bliss, Texas. Moslener explained that the qualification tests will continue on the EDMs until the end of the calendar year.
Development of the accompanying WNW is also well advanced, Moslener said. “We are probably 80 percent complete. It is being developed on the target GMR hardware, and that is probably the only device that allows you to take the full advantage of all of the capabilities of the WNW.
“The last 20 percent covers the integration of several different signals in space, and then have it integrated—not only on the hardware, but it also has to work with some of the other waveforms. The final work we are doing is to bring the integration to a close and undertake the formal testing,” Moslener said.
The number of nodes supported by GMR/WNW is expected to rise to 60 by early 2010, Moslener said. He explained that there have been discussions with the FCS team on whether to increase this, but added that the WNW has already been tested up to 250 nodes in a modeling and simulation lab environment.
“We continue to be on the plan that has been approved by the JPEO,” said Moslener. “Deliveries to the FCS program are on schedule, and testing is on plan and scheduled for completion in December. We will then go into further testing in 2010, to be followed in October by the Milestone C presentation to the government for approval. By that time, we will have gone through all of the security certification with the NSA. Approval of Milestone C will then kick off LRIP, followed by a competition for production in 2011 and 2012.”
The SRW will also be operated by the GMR. Moslener explained what has already been done: “In its earlier version [SLICE/ SRW 0.5], we have already integrated the SRW on the pre-EDM GMR. We have done some field testing with it and we have also provided it to FCS. Later this year, FCS is going into an LUT that they are going to start with the pre-EDM radios, so we are doing an update of the SRW for them for their LUT.
“New versions of the SRW are being provided by the JPEO as governmentfurnished equipment,” he continued. “The new version of the SRW has been instantiated and [ITT] is continuing development. They provide us updates as engineering builds along the way, adding to the capability. We are integrating that latest version in the EDM hardware, which we will provide to FCS as soon as it is done.”
SEVEN WAVEFORMS
Moslener discussed the complexities of integration of all seven waveforms slated for initial use by the GMR. “The most complex of the waveforms was the WNW, but the beauty of that was that we were actually able to develop it on the radio, rather than doing a port of very complex waveforms.”
Each of the waveforms, however, has its own set of challenges. “Some of them have been around quite a while, especially those that run on legacy radios. Some of the newer waveforms were a little easier because the techniques used in developing them were more modern and better understood, but they too have their challenges. What we have to do is to get them running on the GMR. Then we have to get them running with each other, when you’re running four channels simultaneously, with multiple levels of security at the same time,” Moslener said.
The WNW comprises four signals in space (SiS), or waveforms, networked under the WNW’s software wrapper. Williams outlined the differences between the two waveforms: “With the SiS, you literally change the entire communication characteristics; with the SRW you do not. The SRW is much more subtle. Everybody uses the same waveform. The SRW could be operating at different frequencies, or they could be working at the same frequency. Any radio would be able to interoperate with any other radio, but you don’t actually change the fundamental waveform.
“What that means is that all of the abilities to operate in urban canyons, maintain connectivity multi-path diversity, fading problems are all resolved in the same way,” Williams continued. “They are resolved in such a way that it makes the systems scalable, so you can just keep on adding assets to the fundamental waveform or to the fundamental network.” ♦
