Sky-borne Links
Written by Adam Baddeley
MIT 2010 Volume: 14 Issue: 7 (August)
The airborne network of the future will end the residual stovepipes that exist today, with aircraft nodes becoming simply further nodes in the overall network. At a high architectural level, aircraft will be functionally indistinguishable from a land, space or naval platform in terms of their communications.
At the same time, however, the systems that enable that change to take place will nonetheless address the unique and challenging airborne requirements for environmental factors, susceptibility to detection, low latency and the speed at which aircraft join and leave networks.
Airborne links designed to provide stealthy connectivity between tactical air fleets focusing on situational awareness for strike, close air support and air supremacy will be complemented by far more substantive links back into the Global Information Grid designed to transport key ISR and command information back and forth between air, space and terrestrial domains.
Many next-generation airborne networking programs are some way off from that allembracing vision. The most advanced today in terms of fielding is the Multifunctional Information Distribution System Joint Tactical Radio System (MIDS JTRS).
Developed as a four-channel, Software Communications Architecture (SCA)-compliant version of the single channel MIDSLVT now in service, the new terminal is scheduled for operational use aboard Navy F/A-18- E/F Super Hornets in 2011. The terminals are competitively acquired from ViaSat and from Datalink Solutions (DLS), a joint venture between BAE Systems and Rockwell Collins.
First-article qualification of the MIDS JTRS concluded in December 2009, as did security verification testing for the National Security Agency, with an agency technical review board (TRB) subsequently conducting a major waveform certification review.
The successful NSA TRB resulted in vendor certification for both DLS and ViaSat in March. Because it was a co-development between ViaSat and DLS, the design is identical.
Developmental tests, including flight tests, were completed in the FA-18E/F Super Hornet in March, with the program’s operational test readiness review (OTRR) being held in June.
“We received a successful thumbs-up from the OTRR chairman, Rear Admiral Skinner, program executive officer for tactical air, and we are now finishing up the final grooming of the aircraft, making sure everything is in place before starting MIDS JTRS initial operational test and evaluation [IOT&E],” said Navy Captain Scott Krambeck, the MIDS program manager.
OPERATIONAL TESTS
The operational tests were slated to take place at China Lake, Calif., with the VX-9 Air Test and Evaluation Squadron for IOT&E, due to last 10 weeks. An IOT&E report is expected around the end of the year, and if successful, then MIDS JTRS will then go to a full production decision shortly thereafter. The planned initial operational capability for MIDS JTRS on the Super Hornet also occurs at that time.
It is not just the Navy that will benefit from MIDS JTRS, however. Of the 41 terminals already acquired from ViaSat under a competitive contract, five were to be delivered to the Air Force this summer for installation on E-8 JSTARS.
“This spring we were able to deliver to JSTARS some pre-production terminals to begin integration testing. The terminals that JSTARs received in July are production terminals and they plan to continue their integration testing and follow with flight testing,” Krambeck said. In total, 370 terminals are budgeted for procurement.
The Super Hornet fleet, JSTARS, RC-135 Rivet Joint, EC-130H Compass Call and the EC-130E Senior Scout are currently budgeted to receive MIDS JTRS. There is a requirement, however, to extend that to the other platforms of interest that are not yet fully budgeted, including the B-1B, B-52 and F-15E Strike Eagle for the Air Force.
Krambeck noted that Navy’s greatest future interest was for MIDS JTRS in its E-2D and EA-18G aircraft. These future procurements add up to an additional 545 MIDS JTRS terminals.
The terminal is currently configured around two waveforms: Link-16 and TACAN. Krambeck anticipates procurements rising significantly as decisions are made on the waveforms that will be used to utilize the terminal’s additional three but currently unused channels. As part of the first-article qualification, SINCGARS was instantiated for the purpose of multi-channel testing.
“MIDS JTRS is a software defined radio [SDR], and can host any SCA-compliant waveforms. Tactical Targeting Network Technology [TTNT] has been talked about, and some development work has been done on that. We have had inquiries from the Army on the Soldier Radio Waveform [SRW]. Another concept where there is significant interest, particularly for C2 aircraft but which is as yet unfunded, is concurrent multinetting, which essentially runs two separate Link-16 nets on one channel,” Krambeck explained.
Informing future waveform selections is a series of ongoing studies including DoD’s Advanced Tactical Data Link study, which is due to be completed this fall.
“We are heavily involved with the Office of the Secretary of Defense and the services,” said Krambeck. “When those studies are completed, there may be some decision in the FY12 budget of actually funding additional waveforms in the MIDS JTRS. There are all sorts of waveform combinations that could be done, for example, two concurrent multinetting Link-16 nets with two SINCGARS channels, or Link-16 with TTNT and SINCGARS. There are multiple waveform combinations that can be done, and we can do it expeditiously and affordably in order meet the warfighter needs and reduce costs.”
Adding wideband capabilities to the currently narrowband MID JTRS terminal is also an option. Krambeck identified two methods to do this, hosting it across two of the terminal’s three spare channels—seen as the more straightforward approach—or the use of a single channel with its own dedicated transceiver card for a particular waveform.
The same competitive process that has delivered MIDS-LVT terminal will continue, albeit with greater flexibility to innovate via the adoption of the JTRS Enterprise Business Model.
“For MIDS JTRS we intend to have a best-value competition for every production block we run, very similar to LVT. However, each vendor comes forward with better ways to do things. You may see the design diverge and that would be good for the taxpayer in terms of a simpler design and less costly, and that is what we are trying to promote. However, one of the requirements is to be interchangeable; there is still a requirement to have a vendor take a transceiver or card out of their terminal and have it work properly in the other vendor’s terminal. It is not an overwhelming challenge, but it is challenge, and that is the plan forward,” Krambeck said.
COOPERATIVE COMPETITION
In developing the MIDS JTRS, the two teams that normally competed on production orders for MIDS-LVT instead cooperated on the new terminal’s development, in a process dubbed “co-opetition.”
Broadly speaking, ViaSat was responsible for encryption hardware as well as the development of the software associated with the cryptographic portion of the terminal. DLS undertook to work on the portion of terminal tasked with general purpose processing.
“We exchanged detailed information on a regular basis, providing checks and balances,” recalled Paul Baca, vice president of tactical data links at ViaSat. “There were lot of points during the development of the terminal where DLS had an idea of how to make it better or more efficient, which they would convey to us, and if it made sense we would incorporate their comments and vice versa. [Co-opetition] will be beneficial to the government in the long run because both of us have ownership of the entire data package and the design and so they will maintain continuous competition for the life of the product.”
From this point forward, however, both DLS and ViaSat can diverge the configuration of the product, injecting new technology and redesigning certain aspects of the terminal to make them more efficient. Baca said, “MIDSJTRS is nowhere near its final form. It certainly does Link 16 and TACAN, but it has so much more capability to add with additional networking waveforms and additional data link technology.”
ViaSat are currently in the process of identifying areas for investing in order to add capability to the terminal device which has considerable potential. Baca said, “MIDSJTRS has been qualified for the airborne environment and it is sitting there with tons of capability, waiting to be provided to users.”
To illustrate its inherent capability, Baca noted that ViaSat and ITT had conducted a demonstration of MID-JTRS with SRW in 2009. “We were able to adapt one of ITT’s SRW modules and install it in on a MIDSJTRS terminal rather than host the SRW waveform on one of our existing transceivers. At the time, SRW was not as far along as it is today. We are probably going to dust that demo off and bring in some more Army and other high level officials to see if this is going to be useful for them in any of their platforms.”
EXPEDITIONARY EXPERIMENT
The latest outing for the Defense Advanced Research Projects Agency-initiated TTNT program was the Joint Expeditionary Forces Experiment (JEFX) 10-3, held at Nellis Air Force Base, Nev., in May. In the experiment, the waveform was operated from E-2C and E-3 C2 aircraft, F-16 aircraft, Northrop Grumman’s Litening targeting pod, Orion UAV surrogate and special operations forces on the ground.
At JEFX, TTNT’s role was to support a range of scenarios, from conventional war fighting to irregular warfare, in which it was used to support networking at the tactical edge in order to engage fleeting targets more quickly.
“The JEFX experiment is the most prominent event that TTNT has participated in,” noted Scott Green, TTNT program manager at Rockwell Collins. “TTNT has basically been used as the JEFX infrastructure since 2004. We also do other flight test events out at Nellis and China Lake on an ongoing basis.”
Green outlined the benefits of TTNT relative to legacy capabilities. “TTNT is structured around instantaneous egress into the network with no preplanning,” he said. “People who get their hands on it are amazed how easy it is to do that. As long as you have the keys, you can join the network, participate in the network and leave the network at will and do so in a fast moving, dynamic environment.”
Because TTNT is an IP solution, applications can be readily operated over this network. “We have stood up Webcam applications, e-mail applications and VoIP. All the typical Web applications can be used with TTNT,” Green said.
Most of the development activity related to TTNT has been focused on a functional qualification test (FQT) for the waveform requirement, with Air Force and Navy continuing to invest in TTNT in preparation for FQT, scheduled for the end of 2012. Rockwell Collins received a contract to continue developing TTNT earlier this year, and is slated to complete work in mid-2014, working through the Air Force Research Laboratory (AFRL) in conjunction with DARPA.
The MIDS-JTRS terminal was targeted for use with TTNT after discussion between DARPA and the JTRS JPEO in 2004. This was followed by a contract in 2006 in which Rockwell Collins mapped all the requirements for the TTNT transceiver and PA design into the MIDS JTRS under Phase 2C and was completed in 2007.
“We believe that the MIDS-JTRS is still the way to go for fielding and hosting TTNT,” said Green. “The back plane and other components were done with TTNT-type high throughput, responsive, low latency waveforms in mind.”
Defense officials last year opted for the Multifunction Advanced Data Link (MADL) over TTNT for use with the F-35 and F-22 fleets. A key difference between two waveforms is MADL’s use of a directional signal, linking users stealthily, peer to peer. In contrast, TTNT is omni, meaning when it broadcasts, then everyone hears what is going on, which enhances situational awareness.
Green argues for the benefits of both, according to the situation, and believes that this argument is also understood by DoD. “We think that the F-22 and F-35 should have an omni capability too,” he said.
Under the AFRL contract, Rockwell Collins is working on adding a directional capability to TTNT. “We are doing the initial studies to show that TTNT could operate in both an omni and directional arena,” said Green. “You could then easily migrate between omni to directional or directional to omni, based on the situation that the platform finds itself in.”
TTNT is closely associated with a further DARPA program addressing airborne networking—Quint Networking Technology (QNT), which is designed to explore small form factor airborne terminals.
“QNT is a very small terminal, one-twentieth the size of the existing Phase 3 TTNT terminal. The QNT program illustrates that you could put multiple waveforms in terminals that are small form factors. DARPA didn’t have to use the TTNT waveform, but it was selected to be put on the terminal as one of the waveform demonstrations. QNT can support multiple different waveforms in a small form factor.”
DIRECTIONAL NETWORK
But most experts believe that establishing high capacity networks that are only accessible by airborne platforms is counter-productive, and will merely replace one stovepipe for another, albeit more capable one. The view was reflected in the Navy’s Fleet Forces Command’s Trident Warrior 2010 (TW10), in which Boeing demonstrated its 100 mbps+ Directional NetWork System (DNW) in the waters around San Diego, Calif. It linked between an airborne node, the USS Bonhomme Richard and the Marine base at Camp Pendleton to provide a high-capacity extension of a GIGtype network. This initiative was conducted by the Navy’s PMW/A-170 program and Boeing Phantom Works.
“We have been working on this for over 10 years, going back to the end of the 1990s,” said David Bryant, director of advanced broadband networks. “DoD has been monitoring what we have been doing and supporting in terms of acquiring some of the systems that we have been developing, but it has primarily been a Boeing internal investment.”
Boeing’s DNW work is designed to establish a wireless backbone that mimics the capacity of the fixed infrastructure, into which narrowband and lower data rate network could plug.
“Per link, there is max of 100 mbps, and there are multiple links per platform,” Bryant explained. “The basic system is a central unit with the processing, routing and interfaces with other networks. That central unit does the smart stuff; routing determines where things get sent, and then there are antenna transceiver units with electronically scanned phased arrays that can very rapidly form beams between platforms. Each platform can have multiple directional links and then, if you dedicate those directional links to one directional link in one sector, then that can have over 100 mbps.”
By making those links airborne for range extension and from there back to the shore, they can be linked into a protected fiber network such as the GIG, allowing the data burden to be shifted away from satellite communications.
“There are a lot of tactical aircraft out there,” Bryant said. “There is also a lot of discussion as to what aircraft would be used as user nodes or for the relays. We had a helicopter in that position in TW10. An AWACS-type platform flying at 35,000 feet would provide quite a bit more range extension.
“Every system is set up as an automatic router, designed to automatically relay signals through intermediate nodes to get to the final destination,” he continued. “The next step is to start integrating with more realistic platforms that would provide longer range capability.
“DNW is designed to be a mesh network, connecting all nodes, so there would be multiple routes to any destination. That increases the amount of data rate and throughput through the network. As you put on more users in most RF frequency networks, you reduce the total throughput in the network. With DNW it actually increases the throughput as you have more members. We have goals for large number of nodes that would be necessary to support the at-sea battle-group environment,” Bryant said.
AIRBORNE VIDEO
Datalinks to support situational awareness between tactical aircraft in the close fight inevitably differ from those used to support other airborne tasks, not least of which is the communication of high definition (HD) ISR information.
Hughes Network Systems’ latest solution in this field is the Airborne Video Solution, confirming full D-1 video resolution at airto- ground user data rates of over 2 mbps. It also uses TECOM Industries’ KuStream 1000 bi-directional Ku-band antenna and Streambox’s highly secure video coding and viewing subsystem. Using a single device and waveform, users can switch from line-ofsight (LOS) to beyond-line-of-sight (BLOS) communications seamlessly.
“Essentially, it is a single network where an aircraft can be talking to a guy on the ground with a flyaway SATCOM terminal and someone on a ship using the same network, which is network-centric and IP-based,” said Dan Losada, a senior director of the Defense and Intelligence Division at Hughes.
“There have been satellite solutions on aircraft for over a decade, running at rates of 128 kbps and 256 kbps, which is good for Internet or two-way traffic but probably not video,” Losada explained. “There has been a growth in requirements for higher data rate communication into aircraft, using SATCOM. More people want to do 2-3 mbps out of the aircraft for HD video with meta-data attached. To meet that requirement, we have developed a waveform technology integrated with an airborne antenna that you can put on an aircraft going at a typical cruising speed.
“With BLOS communications you can reach places you would not be able to get any throughput with LOS or air to ground directly. We are going up to the satellite so all you have to do is see the sky,” he added.
COTS-based, the Airborne Video Solution technology has already been installed on a commercial jetliner. DoD is now assessing the technology for potential use across a range of applications, such as DISA-led requirement for senior leadership to have access to expanded airborne throughput capabilities.
Hughes also has interest in equipping RC-12N Guardrail aircraft under the medium altitude reconnaissance surveillance system program, and is also eyeing the Navy’s PMA- 290 program, designed to provide a D1/1.5 mbps capability for P-3 aircraft. Losada also reports interest from the special operations community as well as the homeland security and law enforcement communities.
“Having a technical capability doesn’t buy you anything if you can’t manage it,” said Losada. Hughes has spent the past two years creating a new network management system, the HX ExpertNMS, to accompany the waveform. This enables the management of all networks, automatically adapting to the changing conditions of the network without user intervention. ♦
