Real-time satellite communications drive high-capacity bandwidth, combat flexibility.
The Defense Department’s Stiletto experimental naval craft demonstrates communications on the move while cruising at 40-knot speeds off the Virginia coast. An advanced antenna system and X-band commercial satellite demonstrated improved communications, situational awareness and speed vital to the warfighter. During the annual Trident Warrior exercise, sensors aboard the boat were controlled from a continent away via satellite link.
Existing X-band commercial communications satellites with fundamental high power and bandwidth advantages enable communications-on-the-move dexterity. Spacecraft advances and state-of-the-art tracking technology with small but stable antennas facilitate a wide variety of high-data-rate communications for mobile military missions encompassing land, sea and air.
Dramatic demonstrations aboard boats in heavy seas, land vehicles traveling over rough terrain and aircraft bouncing in turbulence consistently supply continuous commercial X-band satellite links with abundant bandwidth. Military demonstrations using XTAR LLC commercial satellites with their 100-watt power and 72-megahertz transponders enhance tactical prowess with antenna apertures as small as 18 inches in diameter.
The commercial X-band satellites were designed and built to provide communications exclusively to
One of many demonstration examples involves participation in the Navy’s annual Trident Warrior exercise. DRS Codem Systems Incorporated confirmed X-band communications on the move (COTM) onboard the Force Transformation Stiletto experimental naval craft. While moving at 40-knot speeds in rough seas off the coast of
“Exercise participants could actually command cameras aboard Stiletto from
Broadband real-time communications at 3 megabits per second (Mbps) on the Stiletto clearly demonstrated beyond-line-of-sight reach-back capabilities. The demonstration also established enhanced situational awareness, enabling remote control of the boat’s integrated electronic suite and secure wireless broadband Internet access for the crew.
“The Stiletto demonstrations worked so well that a DRS COTM terminal was purchased for the vessel, along with an additional six months of XTAR satellite time,” Johnson maintains. “Demonstrations onboard Stiletto are continuing in the
Operating from 7.25 to 8.4 gigahertz, and depending on modem and antenna size, XTAR satellites routinely provide data rates of 150 Mbps. Rates of 200 Mbps also are being demonstrated using a terminal with a 2.4-meter (7.9-foot)-diameter antenna. This is a vast improvement over the 8 Mbps attained with legacy equipment, Curtin explains. “These X-band satellites use two global beams, with one in each polarity, one fixed beam, three steerable beams with no beam movement restrictions and beams that can be stacked over the same area. The satellites demonstrate a capacity of up to 1.6 gigabits per second [Gbps], much of which is immediately available to
The two X-band satellites offer beam cross connections with the ability to route multiple transponders through a single beam. The steerable high-power beams, with near-real-time response, function within minutes from receipt of request, or in seconds using pre-planned positions. XTAR services support high-intensity military operations, Curtin points out, especially for rapidly deploying forces with mobile, high-capacity bandwidth in small terminals.
A two-satellite geosynchronous XTAR constellation provides coverage of two-thirds of the Earth’s surface, from
SPAINSAT is the culmination of planning between
Contributing troops to coalition forces in
The U.S. State Department’s Diplomatic Telecommunications Service Program Office (DTSPO),
The spacecraft enable operating a variety of government-owned terminals and antenna sizes at some 260 diplomatic posts around the globe. These diplomatic sites represent approximately 50
In addition to the DTSPO contract, XTAR has added the Defense Information Systems Agency, General Services Administration SATCOM III and Schedule 70 as contracting vehicles. However, until recent COTM demonstrations, DISA and
XTAR LLC is seeking to shift Defense Department thinking about commercial X-band communications. “People in uniform immediately think Ku-band satellite communications, then Ka- and C-band, respectively. However, these satellites may often be oversubscribed, expensive and difficult to access. We want to convince them to also think of X-band as part of the commercial spectrum, obtaining the capacity for mission accomplishment for a dollar spent. XTAR is not a competitor for DSCS or the Wideband Global Satellite Communications System [WGS], which also uses X- and Ku-bands. We are in a totally different business,” Curtin maintains. One WGS is on orbit, with another two scheduled for launch within the next two years building toward an eventual constellation of six spacecraft.
|An 18-inch-diameter satellite terminal from DRS Codem acquires an XTAR communications satellite during a Special Operations demonstration. The communications-on-the-move antenna mounted on a Rigid Hull Inflatable Boat can maintain contact with the spacecraft at 20-knot speeds in sea states 2 and 3 with bi-directional datalinks at rates of 3 megabits per second.|
Lt. Gen. Steve Boutelle,
“Circa 2005, XTAR worked with the Army in
“XTAR was willing to negotiate a pricing rate that was more than interesting to me as the then-G-6 to provide point solutions for specific high-bandwidth needs in certain areas of the world,” Gen. Boutelle comments. “XTAR also offered to lease, sell or install the modems for the Army. As the [former] G-6, I do not believe the Defense Department adequately assessed the value of XTAR, and the potential benefits that could be achieved, nor did the services pursue potentially valuable XTAR solutions.” Now vice president of the Global Government Solutions Group, Cisco Systems, the general advises government customers on business practices and technology solutions. Cisco has no business relationship with XTAR LLC and, therefore, he is free to address XTAR’s performance.
Another important COTM example is the Space and Naval Warfare Systems Command, which is using small-diameter, mast-mounted satellite antennas on submarines to harness the power of XTAR data rates. The spacecrafts’ transponders limit vulnerable submarine surface exposure times through their inherent speed, reducing transmissions from minutes to seconds. Called the Submarine High Data Rate (Sub HDR) program, demonstrations establish Mbps data rates, replacing typical Kbps rates for submarines. Sophisticated satellite tracking, however, is not necessary for such short durations. The satellite’s position and power allows rapid and easy antenna acquisition.
Developing X-band COTM technology, DRS Codem is demonstrating satellite tracking software algorithms. Using XTAR, the result is high-quality video, voice and data. These demonstrations encompass
With robust Special Operations community interest, DRS Codem also conducted X-band satellite demonstrations on an 11-meter-long Naval Special Warfare Rigid Hull Inflatable Boat (RHIB). These boats perform short-range insertion and extraction of Special Operations Forces, coastal surveillance and resupply missions, Johnson says. “Similar to the Stiletto demonstration, the RHIB, operating at more than 20-knot speeds in sea states 2 and 3, using a small COTM terminal, confirmed bi-directional broadband links and data rates at 3 Mbps over XTAR-LANT. Again, operating off the
Yet another application involves the Mk V Special Operations craft. Capable of speeds in excess of 50 knots and ranges of 500 nautical miles, the Mk V was designed specially to move Navy SEALs and other special warfare forces close to shore. “There are significant advantages in data rates with X-band versus Ku- or Ka-band, especially when intelligence missions differ from command and control [C2] missions. Intelligence platforms tend to uplink more information, where C2 vehicles download more information,” Johnson notes. “Other advantages in using X-band satellites are enhanced performance that avoids rain fade interference, and spacecraft that are not as closely spaced, limiting adjacent satellite interference.”
In addition to
The 18-inch X-band dish antenna is designed to transmit 3 Mbps per second uplink and receive 10 Mbps downlink. This COTM terminal uses an integrated inertial navigation system, open-loop pointing and closed-loop tracking, a direct-drive elevation over azimuth gimbal with high-resolution feedback and an X-band radio frequency transceiver with an L-band interface. The system uses Ethernet remote control and diagnostics and is modem agnostic, according to Johnson. A second-generation DRS COTM terminal uses a lightweight cast structure, a single-board computer for control and stabilization, a low-cost custom navigator and can support X-, Ku- and Ka-band operations.
DRS Codem also provides a ruggedized COTM terminal with the small antenna mounted in a dome atop a high mobility multipurpose wheeled vehicle (HMMWV). This system provides up to 3 megabytes per second of bi-directional link—0.5 Mbps uplink and 3 Mbps downlink, Johnson observes. “The ‘Hummer’s’ modem allows flexible network design, enabling connectivity to other ground mobile vehicles, ships, aircraft and unmanned aerial vehicles. An airborne system, mounted in a window in an aircraft’s fuselage, provides a 75-gigahertz, 1-gigabit-per-second air-to-ground datalink for reconnaissance, surveillance, near-real-time imagery and communications.”
Providing approximately $2 million to DRS Codem, the Army’s Communications-Electronics Command Research Development and
However, the AFRL may have to scale the antenna up to 1 meter in diameter to permit use with the Defense Department’s X-band spacecraft. The AFRL developed this small terminal internally. Several other contractors, in concert with the laboratory, also have developed X-band manportable terminals. Among them is Panther, a rugged system developed by L-3 GCS,
Operating in far-flung regions, Spanish military forces are harnessing technical advances in commercial X-band satellites and employing them for communications on the move.
The Defense Ministry’s military satellite communications system is based on two satellites: SPAINSAT, or XTAR-LANT, launched in 2006, and XTAR-EUR, launched in 2005 “
“We are well-informed about communications-on-the-move technology demonstrations using X-band and have followed all of them since one with the U.S. Army in the spring of 2006. That demonstration employed SPAINSAT, operating at 30 degrees west longitude,” Adm. San Jose relates.
“Our armed forces currently have two COTM vehicles, and three more will become available this year as armored vehicles from a Spanish company, but based on DRS Codem’s technology,” the admiral discloses. “There also are other Spanish companies developing this technology. It is quite clear, however, that this new capability is necessary, and we are implementing it as operational concepts evolve with new conflict scenarios,” he emphasizes.
COTM terminals are not used specifically for special operations missions but rather to extend voice and data via WiMAX, wireless broadband connectivity, to vehicles in a column or convoy of regular forces, the admiral clarifies.
“For Special Operations, a cased terminal is under consideration, using an X-band flat antenna that weighs some 12 kilograms [26 pounds] and provides a 128-kilobit-per-second capability. One person can deploy this system in less than 5 minutes, and it can have broadened spectrum modulation and an Internet protocol coder,” Adm. San Jose points out. New Hampshire-based DRS Codem Incorporated, current partner of Spanish companies in the sale of COTM antennas, has shown interest in this development because the product, he notes, is necessary for U.S. Defense Department operations. The use of X-band will result in replacement of other satellite equipment and in lower costs.
“The trend in satellite terminals toward ‘miniaturization’ over X-band, with an array of small broad-beam antennas, will meet blue force tracking and messaging needs of the Spanish armed forces. Equipment weighing 3 kilograms [6.6 pounds] can be carried in any type of vehicle that proves feasible because of the excellent amplifying capability of SPAINSAT and XTAR-EUR satellites,” the admiral declares.
Numerous examples exist where using XTARs for satellite communications with Spanish forces has proved valuable for tactical operations, Adm. San Jose admits. “One example is the frigate Álvaro de Bazán, which managed to keep the link with XTAR-EUR’s global beam from up to 110 degrees east longitude, with the antenna elevated only 2 degrees. Another example is the use of tactical terminals at 2-megabit-per-second speeds, even in intra-theater scenarios, without a fixed, or anchor, base,” the admiral notes. “With manpack terminals, which can communicate through XTAR’s global beam, an operational advantage is added. The large footprint of