Battlefield satcom

A military force can’t be modular if making a phone call requires building a phone booth. So last year, when military leaders redistributed the Army in Iraq into smaller combat support posts, they did something that would have been more difficult with their tactical command communications system of only a few years ago.

Defense Department planners knew their communications system needed replacing when they sent units to Iraq in 2003. When the 3rd Infantry Division outran its ability to erect line-of-sight communication antennas during the charge to Baghdad, losing its terrestrial radio capacity, the planners knew something needed to change.

They turned to the private sector for a better solution, and they needed it quickly. The result was the Joint Network Node-Network (JNN-N), a system of commercial hardware and software coupled with a trailer-drawn satellite terminal that was deployed in late 2004.

Army Lt. Col. Ann Kramarich can see the difference JNN-N has made. Instead of restricting e-mail and videoconferencing to the forward operating base where the old tactical command communications equipment would have been located, JNN-N allows even platoons to have that same access.

Kramarich was in Iraq for Operation Iraqi Freedom in 2003, when the Army still relied on a Cold War system designed primarily for voice communications called Mobile Subscriber Equipment (MSE). Its performance during the invasion of Iraq led authors of a 3rd Infantry Division action report to call it not viable for future operations. With JNN-N, “we are able to get communications support to smaller levels,” Kramarich said, speaking by phone from Camp Victory, near the Baghdad International Airport, where she is commander of the 44th Expeditionary Signal Battalion.

Communications assets are spread much farther into the battlefield than previous equipment was, she said, adding that she recently visited a Stryker Company at a joint security station that uses JNN-N in the middle of Baghdad.

The Army has spent about $2 billion on JNN-N, outfitting roughly half its force with versions of it. In April, the service awarded a $109 million task order to JNN-N prime contractor General Dynamics for upgrades and more satellite terminals.

Unlike MSE, JNN-N offers over-the-horizon communications designed for a mesh data network. It enables voice over IP and quality-of-service control, and comes in a few pre-packaged varieties.

A typical JNN-N deployment at the brigade combat team level is Humvee-mounted devices connected to a satellite dish.

Bandwidth depends on the terminal and the policy. A Ku-band Satellite Transportable Terminal (STT) generally operates at 4 megabits/sec via a commercial satellite connection. When linked to an AN/TSC- 156 Phoenix terminal, it can go as fast as 8 megabits/sec.

Lower echelons are likely to get Command Post Nodes (CPN), which house much of the gear in ruggedized cases connected to an STT. CPN deployments tend to use time division multiple access modems, which support point-to-multipoint networking.

"The CPNs are really in the highest demand, and it makes sense because of the smaller sites” where the Army is deployed, Kramarich said. In one case, the Army used a helicopter to transport an STT for use with a CPN to a remote site, she added.

Still, MSE wasn’t entirely abandoned. Components of the system underpin a line-of-sight capacity that has remained useful in Iraq, where Army units are now relatively stationary compared with the invasion’s maneuver phase.

At first, JNN-N was strictly a satellite-based system, said Vernon Bettencourt, who retired June 4 as the Army’s deputy chief information officer.

However, line-of-sight radio supports higher transmission capacity, so components of MSE were integrated into JNN-N, he added.

The latency issues inherent in satellite links — which are particularly troublesome when dealing with bandwidth-heavy applications such as the Command Post of the Future collaboration tool — also underscored the need to reincorporate line-of-sight technology, Army officials said. Making small changes to the range in size of satellite terminals, the Marine Corps fielded a 4 megabits/sec JNN-N version it calls the Support Wide Area Network.

“You can imagine what it was like before SWAN came online,” said Marine Corps Capt. Edwin Pena, the network’s project officer. “There were limited beyond-line-of-sight, over-the-horizon communications. It was mostly big, heavy government-furnished equipment.”

The service intends to deploy SWAN at the squadron level, he added.

DO NOT OPERATE IN MOTION
Meanwhile, the one thing JNN-N can’t do is communicate while moving. It’s transportable, it has big data pipes, it’s not locked into line-of-sight constraints — but it’s not communications on the move.

The Army describes JNN-N as quick-halt technology. Setting up the equipment takes about 30 minutes, though a well-trained team can manage it in 10, Army sources say. The Army’s battlefield satellite communications program of record — the Warfighter Information Network-Tactical — was intended to solve the problem of mobile satcom. But in mid-2007, the Army decided to combine the projects.

Following a $2.2 billion WIN-T cost increase, officials folded JNN-N into WIN-T, designating the former as Increment 1 of four WIN-T deployments.

A lot is riding on WIN-T. It is supposed to bring two-way satcomon- the-move to the battlefield. The ability to send text messages via satellite while on the go already exists in programs such as Blue Force Tracking, but mobile satcom is nowhere near the scale that’s necessary, said Col. William Hoppe, WIN-T program manager.

“You can think of it [as] trying to drink coffee through a coffee stirrer,” he said.

Meanwhile, WIN-T has come under scrutiny from government overseers. In March, the Government Accountability Office said the project’s lack of technological maturity could hinder deployment of the Future Combat Systems (FCS), the Army’s keystone modernization effort.

WIN-T has a “turbulent history, including technical challenges,” GAO said.

More recently, House lawmakers cut Increment 2’s fiscal 2009 authorization by $45 million; it’s now down to $287.6 million. In a report accompanying the Defense Authorization bill, which needs Senate approval before being sent to the president, lawmakers questioned whether the Army has a thorough understanding of program funding needs for Increment 3. They also reduced requested funding levels for that increment’s research and development by $33.1 million, to $381.3 million.

Army officials have said the reorganization is an opportunity for synergy between the two systems. Also, the prime contractor for both systems is General Dynamics.

“It was recognized from the beginning that what we were doing…could be an increment of WIN-T,” Bettencourt said.

LIFE IN THE FLOODPLAIN
JNN-N’s predecessor, MSE, was built on the assumption that units might cover 20 kilometers of terrain a day, Bettencourt said. During the Iraqi invasion, they covered many times that distance.

“The area of coverage by the size of units we have over there is also unprecedented,” he said.

MSE’s setup assumed tight Army formations grouped closely together and didn’t allow for dispersed units separated by large amounts of hostile territory.

According to the 3rd Infantry Division report, the mobile part of MSE’s name is a misnomer because the switches were stationary. Users have a range as far as 15 kilometers away while using mobile radio telephones that connect to the MSE switch.

Toward the end of its life, MSE could exchange data messages but only by patching together multiple circuits for a low-bandwidth connection, Hoppe said.

“MSE was really built for a circuitswitched telephone call,” he added.

Army Maj. Curtis Nowak, a signals brigade operating officer with the 5th Signal Command in Mannheim, Germany, recalled what life was like under MSE. Placing a call required a delay-inducing flood search algorithm that inspected the directories of local subscribers kept at various network switches.

“If a node center crashed, you’d have to rebuild that entire phone directory, and people would have to come [into] an affiliate,” Nowak said. “IP routing is obviously an improvement over flood searching.”

But even if technology has not finally made MSE obsolete, Army leaders’ need to designate brigades, not divisions, as the basic building blocks of the service's organization has. MSE’s hub-and-spoke design limited it to high echelons of command. It was cumbersome to set up and needed direct line of sight from one antenna to the next. The Army did not intend to string towers to reach a battalion command post when deploying MSE.

In contrast, each JNN-N has the same ability to connect to the enterprise network, said Maj. Joyce LuGrain, a signal battalion operations officer also with the 5th Signal Command.

“When they go out now using the satellite, they can go anywhere and still do that reachback,” LuGrain added. “That was not really available with MSE.”

‘NOT VAPORWARE’
JNN-N’s rebirth as the first increment of WIN-T has brought some upgrades to the system. It’ll have Ka-band access for connectivity with the Wideband Global Satcom system, previously known as the Wideband Gapfiller Satellite system. Soldiers will have to physically swap the dish feed horn to move from one band to the next, Hoppe said.

Late deployments of Increment 1 will also make a limited introduction of the satellite Net Centric Waveform, which seeks to optimize bandwidth. Waveforms are the wireless equivalent of physical and data link layers, said Joe Simonelli, General Dynamics’ WIN-T director of engineering. “The waveforms are what marry, or connect, these nodes together.”

A separate waveform exists for terrestrial line-of-sight connectivity, which Harris will develop starting with Increment 2, he added. Because of satellite bandwidth and latency issues, Harris’ line-of-sight Highband Networking Waveform will become WIN-T’s preferred link, although the network will also search for the shortest path possible, Simonelli said. If connecting through line-of-sight technology to a particular node requires excessive links between communication systems, “then it’s better for me to go satellite,” he added.

In Increment 2, program managers plan to make the leap to mobile satellite connectivity, but that's not an easy engineering problem to solve. Wireless technology allows users to wander around when connected to a fixed infrastructure, but it gets more complicated when both the user and the network infrastructure are moving.

“The complexity is the vehicle dynamics,” Simonelli said. “Everything is always changing. The other nodes you’re talking to are never the same distance [away]. There are things that come into place to block your way.”

In a static environment, such as today’s JNN-N deployments, operators can compensate for signal interference. If weather becomes disruptive — for example, precipitation distorts satellite signals — an operator can manually boost performance.

However, WIN-T is supposed to function in a vehicle speeding along rough terrain without an operator working the dials.

Beginning with Increment 2, the WIN-T network is meant to be selfforming and self-healing — with certain constraints so it doesn’t waste bandwidth trying to connect to an irrelevant node. But every node of the mesh network will constantly try to synchronize with other nodes, even as parts of the network fall in and out of line-ofsight connectivity.

The network’s mesh qualities also mean that even though some nodes might be quiet, they could be linking from system to system to send data to its destination.

If a node drops out of line-of-sight capability, WIN-T should automatically reconnect the node to the network via the secondary — satellite — link. The switchover should be largely unnoticeable, Hoppe said.

“You may see some jitter…but you’ve still got a signal coming out,” he said.

Videoconferencing could suffer the greatest degradation but not to the point of total signal loss. “This has already been tested,” Hoppe added. “This isn’t vaporware.”

The individual mobile communication technologies that underpin Increment 2 are sufficiently mature, said Bill Weiss, vice president of tactical networks at General Dynamics’ C4 Systems. All that’s left is systems integration. The company is planning a limited user test in March 2009, he added.

THE SHAPE OF THINGS TO COME
Much of Increment 3 is still in the research and development phase. Targeted for fielding by 2014, it’s designated for integration into FCS. That program has problems of its own — one of which, according to GAO, could be WIN-T.

At this stage, engineers must address the size, weight, power and cooling requirements for WIN-T devices that will fit into FCS vehicles.

Other changes are planned, too. For example, network nodes will penetrate further down the command structure. And network routers will receive dynamically upgraded statistics on bandwidth consumption, something they will only have rough knowledge of in Increment 2, Simonelli said. Unmanned aerial vehicles are also due to join the network. Their connectivity could further reduce dependency on satellites. By Increment 3, engineers also hope to have software that will enable one radio to handle terrestrial and satellite waveforms, although two separate antennas will still be necessary. Until then, the system requires a separate radio and antenna for each waveform.

Program officials say they also intend to reduce the cost of antennas during this stage. “The expensive piece of the antenna today is all of that pointing engineering that’s got to happen” to ensure mobile communication, Hoppe said. “There are some boxes out there that do it very well, but they’re also very expensive.”

Plans for Increment 4 are more speculative because much of it will be dedicated to connecting WIN-T with the Transformational Satellite Communications System (TSAT), a constellation of laser-beaming geosynchronous orbiters originally slated for launch by 2009. Now DOD officials say the satellites might deploy in 2018 or 2020 — if they go up at all.

“Any schedule prediction right now is premature,” said Gary Payton, deputy undersecretary for space programs at the Air Force, during a hearing in March of the Senate Armed Services Committee’s Strategic Forces Subcommittee. Subcommittee Chairman Sen. Bill Nelson (D-Fla.) responded by saying, “Well, that's some new information.”

Meanwhile, DOD officials are pondering whether to further develop TSAT.

The delay is a DOD problem that is not specific to WIN-T, Hoppe said. “If TSAT goes in the air, then the Army is going to be one of the bigger users of it,” he added.