Military Band Blue Force Tracking System
Currently there is no affordable military band on-the-move non-line-of-sight (NLOS) or beyond-line-of-sight (BLOS) communications capability available for land vehicles, helicopters, boats or small UAVs. The current state-of-the-art in Satellite-On-the-Move (SOTM) terminals for Blue Force Tracking (BFT) application are units utilizing commercial L-band satellites. The key goal of this project was to develop a low cost, military band, high data rate on-the-move (OTM), small footprint (< 1 cubic foot) satellite terminal which supports Blue Force Tracking (BFT), situation awareness (SA), and C2 missions. Alico Systems has developed a low cost beam steering SATCOM On The Move terminal based on phased array antenna technology with no moving parts. The system utilizes military and commercial X-band satellite. An innovative approach was employed for tracking the satellite without GPS with low cost inertial sensors. Our design supports >128 Kbps forward and >16 Kbps reverse data rate on-the-move with a <0.5 cubic foot volume including the antenna, RF electronics and a spread spectrum modem. The following diagram illustrates the operations concept for a Blue Force Tracking System.
Army Research Opens New Gateway for Mobile Satellite Links
By Robert K. Ackerman, SIGNAL Online Exclusive
A small business innovation research (SBIR) program is allowing U.S. Army researchers to generate on-the-move satellite links that would take advantage of the greater data rates available from military communications satellites. A recent demonstration at Aberdeen Proving Ground, Maryland, proved the worth of this approach for transmitting and receiving vital situational awareness data and command and control messages. This new technology, known as the Small Aperture X-band Antenna (SAXBA), will enable the Army to increase the use of X-band communications aboard military satellites instead of relying on leases with commercial L-band satellites. These commercial satellites have bandwidth allocation of about 200 kilohertz, while X-band offers 2.6 megahertz of bandwidth. Using military X-band systems will enable greater data rates while providing significant cost savings as well as exploiting the advantages offered by the secure military orbiters.
The collaborative effort among the Army’s Research, Development and Engineering Command’s (RDECOM’s) Communications-Electronics Research, Development and Engineering Center (CERDEC) and the Program Executive Office–Command, Control and Communications-Tactical (PEO C3T) has spawned a relatively small system that could give a variety of Army vehicles high-rate satellite communications on the move.
Tat Y. Fung, acting chief, SATCOM Developmental Systems Branch, relates that the two groups have been working on this SBIR for about two years. Alico Systems, Torrance, California, is the company that developed key elements of the system. Its high-performance, low-cost phased array antenna provides the transmit and receive technology. The terminal features phased array antennas set in a 4×4-element, 5-inch-square configuration.
The demonstration featured several terminals receiving live satellite links while mounted on a variety of vehicles. The testing included the Army’s next-generation Force XXI Battle Command, Brigade and Below (FBCB2) Joint Capability Release, which displayed location updates. This would be a primary application for this technology, Fung allows. He notes that the demonstration also validated the concept of attaching a Blue Force Tracking terminal to an external modem for running commercial applications on the move, particularly high-quality voice communications.
Rich Hoffmann, lead electronics engineer, SATCOM Developmental Systems Branch, relates that the system’s radio frequency performance in its ability to transmit and receive worked as expected. FBCB2 data rates are relatively low, yet the demonstration achieved higher rates. Ultimately, the technology should permit substantially higher data rates, which translates to better situational awareness and command and control on the move.
This demonstration used a commercial X-band satellite to validate the concept of X-band on-the-move connectivity, but it is designed ultimately to use Wideband Global SATCOM (WGS) satellites. Hoffman notes that issues remain with regard to obtaining allocations for a military communications satellite.
Hoffmann states that more work remains for effective integration and tracking. He cites one example of how chips positioned too closely were generating unacceptable amounts of heat, so that part of the configuration would need to be re-designed. However, these problems are logistics-based and should be solvable.
Fung adds that the next step in antenna development will be a 16×8-element phased array configuration, which will provide connectivity with higher throughput. Applications in addition to FBCB2 will be tested, Hoffman says, along with a distributed aperture approach. This would allow multiple apertures to support high-data-rate connectivity on the move.
As with future testing, obtaining the technology is contingent on adequate funding, Fung notes.
Future satellite communications will bear no resemblance to Star Wars
By Ms. Sharon Rushen (RDECOM)
Researchers are redefining the costs and performance of Soldier satellite communications on-the-move to address current and future challenges.
The Research, Development and Engineering Command’s communications-electronics center, or CERDEC, in collaboration with Program Executive Office, Command, Control and Communications Tactical, or PEO C3T, is looking to replace the L-Band SOTM terminals supporting Force XXI Battle Command Brigade and Below, or FBCB2, with X-Band terminals.
This effort is being done through the transition of PEO C3T’s Army Small Business Innovation Research project, Small Aperture X-band Antenna, or SAXBA, to the Army Technology Objective, Affordable Low Profile Satellite, or ALPS, program. The ATO program aims eliminate the need to use the expensive, commercially-leased L-Band satellites by further developing a SOTM terminal that is able to utilize the X band portion of the DoD-owned Wideband Global System.
FBCB2, a battle command information system in military vehicles, utilizes the L-Band SOTM terminals to provide situational awareness from brigade to vehicle level forces, said Joe Shields, a branch chief of CERDEC’s Space and Terrestrial Communications Directorate’s SATCOM Systems Division.
The costs associated with leasing the commercially-available L-Band satellite bandwidth are estimated to be $40 million a year, said Tat Fung, technical lead for the project. “The benefit is really its reduced life cycle costs, which is the annual satellite leasing cost of the L-Band,” said Fung.
In addition to the cost concern associated with the L-Band, other issues like security and accessibility are what prompted Shields and a team of experts to research alternative options. Because commercial satellites have fewer restrictions on who can utilize them, the military has to compete with commercial users which has, at times, resulted in lowered bandwidth availability for troops overseas, he said.
“For the Soldiers in Afghanistan, L-Band access is a challenge, and right now there are X-Band satellites right over theater,” Shields said.
Because of its government-only availability, utilizing X-Band, one of the WGS bands, can potentially enable better access to communications.
“You’ve got thousands of units out in the field; whoever wants to transmit has to lease the bandwidth. L-Band right now comes only from commercial sources. WGS is government only, you don’t have to pay for the bandwidth, you just have to go through the process to be approved and validated for use,” Shields said.
While cutting costs is one aim of the SAXBA project also aims to add functionality by utilizing high performance phased array antennas, transceiver and antenna pointing technologies that can be electronically steered rather than mechanically to track a communication satellite while on the move. The technologies are scalable to provide low-profile distributed antenna systems for various land, air, and water platforms with different data throughput requirements.
The low-profile phased array antennas will also help to ensure safer operation for deployed Soldiers on platforms with SATCOM on-the-move communications.
“If you have seen some of these mechanical tracking on-the-move dish antennas that look like Star Wars’ R2D2, they can be a bullet magnet. They are highly visible. SAXBA shows that we are making antennas much smaller – they are harder to see in addition to being cheaper to use and having a lower vertical height,” Shields said.
“When you are in a bouncing humvee [Highly Mobile Multi-purpose Wheeled Vehicle or HMMWV], you don’t have to worry about making an antenna dish point at a fixed spot in the sky far away, because doing everything electronically is almost instantaneous and much more agile. The Soldiers out there in the field probably want something they slap on the top of the vehicle, turn it on and ignore it, which is one of the things we are trying to do.”
To further prove-out their work, Shields and his team are conducting on-the-move antenna testing in May. In the summer, they will test the fully integrated SAXBA BFT terminals, from Alico Systems Inc., in field-like environments, incorporating the technology onto military vehicles. Shields hopes to demonstrate the terminal’s capabilities as a potential replacement for L-Band use.
“We are bringing solutions into a military SATCOM environment.” Shields said. “There’s going to be a need for all these sorts of SATCOM antennas and we are just filling another niche now.”