To operate in today’s theaters — with 38,000 NATO and 47,000 U.S. troops in mountainous Afghanistan and 115,000 U.S. troops in the deserts of Iraq — the military needs even lighter and more capable ground systems that provide beyond-line-of-sight communications. With the restrictive protocol of limited troop engagement, the need for real-time linkage on surveillance platforms and command and control structures has been elevated. What are the latest efforts to meet the warfighter’s needs, and how are these efforts being impacted by growth in the use of communications-on-the-move, communications-on-the-pause and networking-on-the-move terminals? Will the future yield high-power, commercial X-band communications satellites designed to meet growing commercial and military bandwidth demands? What spectrum will help satisfy the U.S. military’s huge demand for space-based centric warfare?

Pentagon’s insatiable Demand for bandwidth

With the cancellation of TSAT, the U.S. Air Force’s advanced satellite communications and the expected move away from space-based projects in future Department of Defense budgets, it appears one of the primary means of closing the expanding bandwidth gap of the warfighters could be X-band provided by commercial operators. David Cavossa, vices president of operations for CapRock Government Solutions, says, “Now that the reality of the TSAT cancellation has set in, there are two segments of opportunities. One, is X-band and Ka-band. The Department of Defense needs more commercial X-band and Ka-band, and … that’s where CapRock is positioning itself to be a leader in the future. There are already a lot of players in the Ku-band and the C-band. We have a lot of services today in [those bands], but we want to be the leaders for the military in X-band and Ka-band. The second segment, which we really don’t have a play in today, is hosted payloads, and that’s where companies like Intelsat General and SES Americom and the satellite operators are really going to lend a helping hand to the Department of Defense in the near future and already have, as you’ve probably seen. The payloads, I think, are going to help meet some of that need when TSAT went away.”

The U.S. Defense Information Systems Agency is the sole authority for providing commercial satcom services to the Pentagon to augment the military satellite communications system. According to DISA PEO and Satellite Director Bruce Bennett, “With the cancellation of TSAT, options that have never been in play before are now on the table. We have always depended upon commercial satellite to fill our voids. We don’t see that changing any time soon. … Our communication needs are following in strict accordance with Gordon Moore’s Law. So our requirements keep growing faster than we can put things up, so what you’re seeing is we need it everywhere and we need it yesterday.”

X-band As Force Multiplier

The Defense Satellite Communication System-3 (DSCS) constellation has supported the Pentagon’s communications system, the Army’s ground mobile forces, the Air Force’s airborne terminals, Navy ships at sea, the White House Communications Agency, the U.S. State Department and U.S. intelligence agencies. Some of those duties will be picked up by the Wideband Global Satcom (WGS) constellation, says U.S. Army Col. Patrick Rayermann of the U.S. National Security Space Office. “The United States has already agreed to fund WGS 4 and 5. The AMD (Australian Ministry of Defense), in exchange for receiving an assurance that when the AMD deploys forces or requires wideband that a portion of the overall capability of the constellation will be available on a priority basis, …transferred the funding to procure the WGS-6 spacecraft. They are all funded and in production. WGS-5 is mature and WGS-6 has begun. … We have no reason to doubt that we will have six healthy WGS spacecraft in orbit within the next few years.”

But that will still leave a gap in the bandwidth needs of the U.S. military, one that likely will be filled, in part, by commercial operators. “One of the real issues is going to be whether the government, if it’s commercially used, is willing to pay for the capacity that will be required to use these really small terminals, and up until now, there’s been a real reluctance to let these kind of very small terminals be used on WGS because of the amount of capacity they demand,” says Denis Curtin, COO of Xtar, a joint venture of Space Systems/Loral (SS/L) and Spain’s Hisdesat, that provides X-band services via the Xtar-Eur and Xtar-Lant satellites. The services are designed to replicate the DSCS and WGS footprints for customized X-band and communication services to United States and other governments.

Hisdesat is at the heart of Spain’s military satellite communications strategy, and the company’s satellites use “the most advanced technologies available today,” says Miguel Angel Garcia Primo, COO, Hisdesat. “This system provides our armed forces with new uses and capabilities, such as communications on the move, use of manpacks, even within global coverage, and increased traffic through all terminals in general and through the smallest terminals in particular, for example, in the case of submarines. The major challenges are related with the upgrade of the network to be able to fully exploit the satellite capabilities both in term of higher data rates and larger interconnectivity with the concept of everything over IP and with a final goal of a network centric.” Hisdesat’s system is fully compatible and interoperable with NATO systems, and “there is also a great flexibility and a dynamic mobility (fixed, mobile and transportable terminals) connected through several steerable or global beams,” he says.

But there are problems with the U.S. military’s use of commercial X-band services, according to Air Force Col. Donald Robbins, commander, Wideband Global Satcom Group, Milsatcom Systems Wing at Los Angeles Air Force Base. “Most U.S. satcom-on-the-move terminals are in the Ka-band and cannot use Xtar, since it is only X-band. The Xtar spacecraft utilizes the opposite polarization from WGS. Terminals have to be dual polarization capable to communicate with both spacecraft. It can be complementary for larger terminals likely to have the dual polarization capability. … Any future WGS spacecraft will replicate the current design, and WGS is not driving the development of new terminals.”

Terminal Technology

The commercial providers are working to improve terminal technology, Cavossa says, “In general, the military wants smaller terminals, more mobile terminals, and they want to be on the move when they’re communicating, so that’s at a high level, one of the trends that we’re seeing going forward. The other trend is they want more bandwidth, but they’re moving toward other bands.”
Darren Putman, director, L-3 Communication Systems-West, Army Satcom, says “X- and Ka-bands are circular polarized signals, and there’s right- and left-hand circular polarization. Key advantages are frequency reuse, which allows you to transmit and receive on a similar frequency. It also prevents you from self-interference as long as you transmit on right-hand and receive on left- hand polarization.”

Shawn Baerlocher, director of milsatcom programs for Harris Government Communications Systems Division, says that “because of the mountainous terrain in much of the country, satellite communications in general is becoming more important since line-of-site communications there is impacted by rugged terrain. Our tactical terminals in use today by the U.S. Marine Corps include the Lightweight Multi-band Satellite Terminal and Rugged, Deployable Satcom Terminal, both of which are multi-band, operate at C-, X-, Ku-, and Ka-bands. Additionally, we have several tactical antennas in use by the military services today, these include the single-band [Lightweight High-Gain X-Band Antenna] and the tri-band [Large Aperture Multi-band Deployable Antenna], which supports C-, X- and Ku-bands. Our newest antenna, the Modular Advanced Quad-band Antenna, supports C-, X-, Ku-, and Ka-bands.”

CapRock is developing a small, highly portable terminal designed to provide communications-on-the-pause capabilities, says Cavossa “It would sit in a backpack and be less than 1 meter in size and include everything you would need in that backpack.” Starling Advanced Communications is introducing the StarPack, an on-the-fly antenna for carry-in/carry-out that offers high-speed broadband connectivity from anywhere. According to Marty Broadwell, vice president, business development, COTM systems for EMS Defense and Space, the company has “designed and demonstrated a prototype X-band antenna using a low-loss waveguide antenna that provides orthogonal circular polarizations for transmit and receive. The antenna is scalable for a variety of applications including ground and airborne mobile,” he says 

Positive Growth for Military COTM

X- and Ka-band are primary spectrum frequencies for the military, but so are the commercial frequencies. Even L-band is growing as seen with SkyTerra Communications with the U.S. National Guard and outside of the continental United States for blue force tracking. “We see tremendous growth in the utilization of terminals for on-the-move or on-the-pause systems, and we see more and more of the deployed (military) teams are getting small aperture terminals,” says William Schmidt, vice president, government services, for Xtar. “… There are more and smaller terminals starting to be deployed or continuing to be deployed within US and Allied forces. For example, these small portable manpacks that the Spanish forces are using, the Indra manpacks, are a great example,” he says.

“The Department of Defense’s expanding needs of communication will always grow,” says Putnam. “They’re always going to expand. Will there be enough and with capability in our satellite networks to satisfy all their needs? I don’t think that we can ever make that statement.”

According to Bennett, “X-band is a good frequency for us to use, and we are going to continue to use it. However, we are trying to get away from being dependent upon anyone single frequency or one single band, because frankly, we are going to go wherever the bandwidth is and that is what we will use.”

The systems, technologies and processes of communications on the move and on the pause will have an impact in today’s and future operations.