By Peter J. Brown

When it comes to delivering bandwidth in the battlefield, the U.S. military is in what is best described as rapid-recovery mode. The liberation of Kuwait more than a decade ago was accomplished with what is now considered a mere trickle of satellite bandwidth when contrasted to the enormous flood in demand encountered today in support of ongoing operations in Iraq and Afghanistan.

And what a difference in the two campaigns. Not only has the satellite bandwidth requirement mushroomed, but Operation Iraqi Freedom and Operation Enduring Freedom represent the first live use of Web-based warfare. Coalition commanders in the field have the ability to communicate using a collaborative software package known as the Information Work Space. The entire network, known as the Combined Enterprise Regional Information Exchange System, constitutes a military communications breakthrough and was in its infancy at the time of the first Gulf War.

While commercial satellite service providers have been able to help meet the demand for bandwidth by U.S. forces, the Department of Defense (DoD) has studied its current dependence upon commercial partners and devised a new set of solutions intended to meet existing requirements as well as to prepare for enhanced Network Centric Warfare (NCW) in the future.

To make true horizontal fusion a reality–which is what NCW enables–a high-bandwidth multimedia cloud must permeate the battlefield, and this can only be made possible by including the resources of a global multi-band satellite network. But all the existing Milstar, UHF Follow-On, which hosts the Global Broadcast Service (GBS), Defense Satellite Communications System (DSCS) and other Pentagon communication assets high overhead are worth very little if the ground segment is not performing as it should or is missing altogether.

DOD Teleports Preparing For Advanced Military Satellite Communications Systems

With the commissioning of the latest teleport in Hawaii in April 2004, the DoD Teleport Program, initiated by the Defense Information System Agency (DISA), now encompasses six sites worldwide. The teleports empower NCW and comprise a vital part of the DoD’s transition to the Transformational Communications Architecture. The teleports serve as gateways between the Global Information Grid and warfighters seeking access to the Defense Information System Network (DISN) services using all military and commercial satellite communications frequencies.

Multi-band terminals are the tools enabling warfighters to, among other things, tap into the DoD teleports to reach DISN services such as the Defense Switch Network, the Defense Red Switch Network, the Unclassified but Sensitive Internet Protocol (IP) Router Network, the Secret IP Router Network, the Joint Worldwide Intelligence Communications System and video teleconferencing.

The expansion of DoD teleports through fiscal year 2010 is mapped out in a three-generation plan. By the end of fiscal year 2006, the architecture being implemented today should be completed with existing Standardized Tactical Entry Point sites ready for C-band, X-band, Ku-band, UHF and EHF traffic. By fiscal year 2007, military and civilian Ka- band should populate the DoD teleport system. Systems such Advanced Wideband System, Advanced EHF System and the Advanced Narrowband System should be integrated and operational by the end of fiscal year 2012.

The DoD is pursuing a number of terminal development efforts to enable improved communications, including the U.S. Air Force’s family of Advanced Beyond-line-of-sight Terminals and Ground Multi-band Terminal (GMT) programs; the U.S. Army’s KASAT, Phoenix and KAStars efforts; and the U.S. Navy’s EHF Follow-On-Terminal and Navy Multi-Band Terminals.

These terminals are being developed to work with the Wideband Gapfiller Satellites, the Advanced EHF satellites and the Mobile User Objective System (MUOS) satellites. All of these systems are scheduled to begin service by the end of the decade.

"The mobile and portable terminals of the future will achieve significantly better performance due to two major factors," according to a DISA spokesperson. "First, the milsatcom space segments will be much more capable with respect to power and antenna coverage. A single [Wideband Gapfiller] satellite can supply the capacity of the entire DSCS constellation.

"On the terminal side, the use of very efficient forward error correction coding, the super conductive technologies for [radio frequency] reception and conversions, and the miniaturization of electronics being pursued in the cellular phone and Joint Tactical Radio System development will be major contributors," the spokesperson says.

DISA also points to other trends being pursued by the DoD and the industry, including:

• Higher bandwidth and data rates combined with a proliferation of platforms such as unmanned aerial vehicles
• Tactical terminals will be deployed to lower echelons of the military resulting in increased traffic
• Broadband communications on-the-move
• Embedded terminals with connections to line-of-sight and satellite communications
• Handheld broadband services
• Convergence to IP (voice, video, data) and Web-based services

To meet these new and expanded requirements, terminal development programs are focusing on technologies such as direct radio frequency to digital conversions, software-based radios, conformal antennas, multi-simultaneous-band operation of antennas and embedded encryption, the DISA spokesperson adds. The Pentagon is also looking at adaptive coding and modulation techniques that can sense the quality of satellite links to optimize performance in varying weather conditions.

"Everyone is looking to get into solutions that give them more performance with smaller apertures for enhanced portability," says David Beering, principal partner of Chicago- based Infinite Global Infrastructures LLC. "Definitely keep a close eye on SOTM — satcom on-the-move aka COTM or communications on-the-move. I think the emergence of realistic satellite alternatives for mobile platforms will be pretty big in the next four to five years, especially as new satellite platforms like [Wideband Gapfiller, Advanced EHF] and MUOS hit the sky."

According to industry experts, reducing terminal size, weight and power, improving antenna-pointing performance, providing multi-band performance capability, and doing all of this at a reduced cost involves creating a capability that does not exist today.

"As with any tactical terminal, the challenges have been and remain the ability to withstand a deployed environment," the DISA spokesperson says. "Deployed environments can vary from hot desert to extreme cold climate, be very difficult and require special designs not usually found in commercial satcom applications. Additionally, as the military user community requirements for higher data rates in smaller packages grow, terminal designers have had to develop some innovative approaches."

One example of a new innovative design is the use of commercial direct broadcast satellite technology, which is used in mobile applications and modified for military applications on airborne and ground mobile platforms, the spokesperson says.

The World According To CECOM

The U.S. Army sees military satellites as a critical part of current and future communication architectures. According to Rich Condello, project manager for Warfighter Information Networks-Tactical (WIN-T) at the U.S. Army Communications and Electronics Command (CECOM), the scope of this activity is enormous.

"As the battle space stretches, terrestrial communication systems do not have the range or the capacity to support network operations," says Condello. "Additionally, the Army is fielding capability to lower echelons in the architecture, which is also driving the demand on satellite capacity. Satellite communication is used to support both reach and reach-back operations and interface to joint and coalition forces."

CECOM is fielding and upgrading multiple tactical ground terminals to meet its future communications needs, including the Secure Mobile Anti-jam Reliable Tactical Terminal (SMART-T) to access Milstar satellite capacity, and down the road, Advanced EHF satellite capacity.

The GBS Transportable Ground Receive Suite and the Transportable Injection Point provide high-speed access to data and multimedia information such as unmanned aerial vehicle imagery, maps, weather, logistics and air tasking orders to deployed and garrisoned forces worldwide. An IP upgrade of GBS terminals is underway.

Using commercial Ku-band, the U.S. Army is fielding the Joint Network Node (JNN) hub and trailer mounted terminals. JNN will be upgradeable to support Wideband Gapfiller Ka- band traffic when the system is operational, which is slated for 2006.

"As the JNN architecture matures and the WIN-T program is fielded, the emphasis on static command posts will shift, and the Army will begin to deploy more mobile ad-hoc architecture with a greater dependency on satcom," says Condello. "We will see a shift from larger VSATs to more on-the-move satcom that will be capable of operations on both commercial and military bands."

Condello sees challenges ahead surrounding the development of the right architectures and capabilities that efficiently utilize satellite communication resources, including meshed topologies and support for IP voice, video and data traffic. Coverage and capacity that will support a mix of both larger, 2.4-meter, 1.2-meter and on-the-move terminals over vast terrain represent another area of concern. Network management systems that allow for the dynamic re-allocation of resources to support surge requirements, novel antenna systems, the secure delivery of bandwidth-on-demand, along with the development of waveform techniques that will enable the efficient usage of small on-the-move terminals, scale to support large numbers of users and avoid adjacent satellite interference are also on Condello’s list of concerns.

"We need more capacity and more efficient satellite loading as the number of small [on-the-move] terminals grows in the architecture," says Condello, who is concerned about the affordability of the ground terminals as well as techniques to ensure that reliable, networked communications are provided to the warfighter worldwide.

"The architectures we are developing are three-tiered – ground, air and space," Condello says. "We need all three layers to ensure we have a robust network. That being said, we are channeling resources in all areas to develop this capability."

Near Space Solutions Are Emerging

Out on the horizon is the U.S. Air Force’s laser cross-link-equipped Transformational Satellite Communications System (TSAT). Among other things, TSAT will feed into the near space grid alluded to by Condello, perhaps by beaming signals to KC-135 tankers, for example, which have already been equipped with external Internet relay antennas as part of the roll-On, beyond line-of-sight enhancement system.

Hybrid laser cross-links involving aircraft and satellites will play a significant role in the future. A C-135E aircraft designated as a command, control, communications, computers and intelligence airborne test-bed by the Air Force Research Laboratory has the advanced Optical Radio Frequency Combined Link Experiment (ORCLE) optical datalink ready to deliver data at speeds of 2.5 gbps.

In 2006, airborne ORCLE network demonstrations will include hybrid protocols for networking and multiprotocol-label-switching-based traffic provisioning. This will lead ultimately to a role in the DoD’s Transformational Communications Airborne Technology System demonstration, which includes an integration of GBS feeds and tactical targeting network technologies.

While work progresses on the GBS Ground Receive Suite terminal, the Advanced Wideband Terminal will be used on airborne platforms to provide a wideband and protected communications capability in support of joint mission areas such as nuclear and non-nuclear platforms, special air missions, mobility airlift, special operations, search and rescue, and para rescue forces.

The Ground Multiband Terminal (GMT) will provide support to help meet worldwide communications requirements using the Wideband Gapfiller satellites. GMT will replace the Air Force Ground Mobile Forces terminal. With quad-band capability, GMT will provide users with a lightweight, scalable terminal with a 10-fold increase in throughput capacity.

So what will enable the next generation of mobile or portable satcom terminals in particular to outperform terminals in use today?

"Better space segment involving newer satellites with more power, better radio systems with advanced channel coding, channel sharing and modulation schemes will add to this in large measure," says Beering. "So, too, will more innovative packaging incorporating form factor improvements, including innovative concepts such as a new inflatable satellite antenna."

As for the terminals in use today and some in the pipeline, here is a quick sample:

• The Joint Network Transport Capability-Spiral (JNTC-S) is one of the Army’s Bridge to Future Networks concepts. The terminal is aimed at augmenting existing solutions such as the Single Channel Ground and Airborne Radio System, Mobile Subscriber Equipment (MSE), and the Tri-Services Tactical Communications system in advance of the deployment of future WIN-T systems. In a recent interview, Maj. Gen. Janet Hicks, commanding general, Army Signal Center and Fort Gordon, Ga., said that some units will have a mix of MSE and JNTC-S terminals for several years, while the scheduled deployment of WIN-T is being accelerated as quickly as possible.
• The AN/PRC-117F Special Operations Forces extended frequency range, dual antenna radio allows single-channel and demand-assigned multiple access UHF satcom links. The 10-pound device is capable of transmitting at 64 kbps with features including auto retransmission request and embedded security.
• More than 4,500 PSC-5D or Multi-Band Multi Mission Radio tactical terminals have been fielded to date. The software definable terminal provides secure voice and data communications.

Phoenix Rises

At the Army Network Enterprise Technology Command the door has opened for not only tri-band terminals that can downlink and uplink signals, process them and deliver them directly to end users, but also to the Army Phoenix quad-band terminal, which will replace Army Ground Mobile Forces Tactical Satellite Communication Systems.

The Phoenix tactical terminal program is a transportable multi-band, multi-channel terminal that operates in the C-, X- and Ku-bands over commercial and military satellites with the capability to add Ka-band for operation over the future Wideband Gapfiller Satellites. The new tri-band and Phoenix terminals seem ideally timed to take advantage of Xtar-Eur, the new satellite that can provide a direct X-band link to the Middle East.

In early May, the U.S. Army’s 7th Signal Brigade completed its first field trials of the Xtar-Eur satellite using a tactical ground AN/TSC-85C terminal with both a standard 16- foot Army Lightweight High-Gain X-band Antenna and an 8-foot tactical satellite antenna. Data rates of more than 100 mbps were achieved with the 16-foot dish, outperforming DSCS satellites.

The U.S. Army’s High Capacity Communications Capability study is aimed at the development of a modular and scalable architecture for the next generation Joint Service Communications Capability. The capability leverages future wideband space architecture in a single platform that includes high capacity line-of-sight; intelligence, surveillance and reconnaissance; and protected communications on-the-move. The system will take advantage of next-generation digital devices, advanced materials currently being studied for monolithic microwave integrated circuits and innovative solutions for communications on-the-move antennas with an emphasis on a modular, open system design.

Issues remain for Satellite Program Stability And Reliability

A couple of unwelcome events in 2005 have sent a clear signal to the military satellite community. While we can talk about 21st Century high-performance links and future technological breakthroughs, we need to first examine the satellites, and the workflows and support systems surrounding them.

The flight test failure of the Ground-based Midcourse Missile Defense program last February was attributed to a combination of quality control and improper silo configuration. Quality control issues surfaced again when a GPS satellite launch was delayed this past spring. A relay on the spacecraft had somehow avoided destructive physical analysis.

While these recent missteps do not bear directly on the satellite communications universe, they constitute a wake-up call. Little oversights or slip-ups that could have been avoided altogether are often symptoms of a bigger problem. It is clear that systems management, quality control and oversight need to be reinforced, from the ground up.

Peter Brown is Via Satellite’s Senior Multimedia & Homeland Security Editor.