Satellite Links Aid Transformed Force

September 2005
By Robert K. Ackerman
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At the heart of the 101st Airborne Division (Air Assault) Joint Network Node (JNN) system is its Ku-band satellite communications trailer. The 2.4-meter dish system features auto-erect, auto-acquire capabilities that enable users to establish satellite connectivity quickly.
Redefined forces require a new approach to mobile communications.

To get where it wants to go and know what to do when it gets there, the U.S. Army’s 101st Airborne Division (Air Assault) has incorporated satellite links with a large dose of commercial technology to provide connectivity throughout the battlespace. These mobile systems provide connectivity between battalion-level forces and division headquarters, and they tie into a hub that serves as a gateway to the Global Information Grid.

The division was one of the first to be reorganized under the units-of-action transformation concept (SIGNAL, September 2004, page 23). This transformation eliminated the division’s signal battalion by embedding signal capabilities into each unit of action. To provide necessary communications links for these units, each one is equipped with a Joint Network Node (JNN). These JNNs also are placed with each major division command post, and the division’s four maneuver units of action receive an additional JNN to support their tactical operations centers and their brigades.

Because it relies on satellite linkage, the JNN largely is terrain independent. It includes some line-of-sight capabilities for connecting with different levels of forces. Built by General Dynamics C4 Systems, Scottsdale, Arizona, it is based on commercial off-the-shelf technology, which gives it a greater capability for tying into various other technologies in use.

“We literally have gone from MSE [mobile subscriber equipment]—late-1970s to mid-1980s technology—to the new age of an IP [Internet protocol]-based world in one jump,” declares Maj. Troy Douglas, USA, G-6, network operations, 101st Airborne Division (Air Assault).

Maj. Bernd Kohler, USA, network engineer in the division’s G-6, explains that the division’s communications architecture comprises two hub nodes, 14 JNNs and 38 command post nodes for a 2/14/38 architecture. This hub-centric, satellite-based architecture ensures that everyone is just “one satellite hop away from the hub,” he points out. The hub would be located in a safe site to serve as the point of presence for Defense Information System Network (DISN) services. Maj. Douglas points out that the hub is the key to the entire system. This hub must provide access to the Global Information Grid from its sanctuary location.

JNN capabilities are significant at the battalion level, where habitual MSE support was lacking. This new architecture provides for high-bandwidth data service beyond push-to-talk, the major notes. Now, personnel at this level have telephone, secret Internet protocol router network (SIPRNET) and nonsecure Internet protocol router network (NIPRNET). Battalion level also can avail itself of Army Battle Command System capabilities, which previously were limited to brigade level.

Brigade level can see an increase in data throughput by as much as 100 percent. More telephone capability also is available, as brigade tactical operations centers can increase their number of telephones from 30 up to 46 or more.

Maj. Douglas notes that the system’s bandwidth “quickly gets chewed up with various overheads and basic requirements.” While the system can handle 78 megabytes, most of those are dedicated to intra-division links. Only 4 megabytes are available for external links.

Each of the 14 JNNs takes the place of a node center, and they enable the functionality found in a small subscriber node. These JNNs provide switching functionality and subscriber functionality in a single assemblage. This contrasts with previous node centers that functioned primarily as tandem switches, Maj. Kohler notes.

The JNN is sited in a standard S-250 shelter. The command post nodes, which comprise five transit cases and are not mounted in a shelter, are located at battalion level.

The network employs both frequency division multiple access (FDMA) and time division multiple access (TDMA). Maj. Kohler explains that each JNN has one FDMA link back to the hub. The hub features a Network Equipment Technologies’ Promina 800 multiservice access platform, while the JNN has a Promina 400. This multiplexing configuration provides DISN, SIPRNET and NIPRNET services.

These JNNs also create one TDMA mesh per unit of action. The command post nodes and the hub all are part of that JNN TDMA mesh network. This capability gives each JNN two options for connecting with the hub. While each battalion command post node has only TDMA mesh connectivity, it still can communicate with its parent JNN or with the hub using the full range of DISN services.

Each JNN includes about seven routers. SIPRNET connectivity is tunneled through NIPRNET channels using Taclanes. A Vantage switch ties in MSE links. A FLEXMUX multiplexer with a fiber optic modem provides entry for a high-capacity line-of-sight radio shot.

A private branch exchange (PBX) unit handles up to 96 subscribers. The voice architecture is multifaceted in that it can accommodate both voice over Internet protocol (VoIP) and traditional telephony. This permits continued use of a secure telephone unit, or STU. The JNN provides both red and black voice connectivity in PBX and VoIP.

Maj. Kohler notes that the JNN has a lot of information assurance built into it. From firewalls to encryption, the system has measures that were not common at this level. These include Tier One and Tier Two security.

The system also provides a “pretty robust” battlefield video teleconferencing capability, the major relates. It allows H.320 and H.323 multipoint multisession video teleconferencing. The equipment can interface via Ethernet for H.323 traffic or via KIV-7 encrypted modem for H.320 links. Not only can a brigade host its own voice conference call, but also it can host the same capability in video among its battalions.

Each JNN unit comes with an onboard 10-kilowatt generator and an air conditioning unit that cools the equipment on the trailer. David Holzwarth, field engineer for DataPath, Atlanta, states that the satellite system has auto-erect, auto-acquire capabilities for its 2.4-meter dish. His company provides the Ku-band trailers and the modems for the system. General Dynamics provides the networking side of the system.

Commercial hardware makes up much of the electronics support gear in the JNN Curbside Shelter.
A VertexRSI 123T serves as the JNN’s tracking system. Holzwarth explains that this unit simplifies tracking for the soldier running the JNN. That soldier merely needs to know the satellite’s longitudinal position, and the 123T will scan through satellites in that region of the sky until it identifies the correct orbiter from its beacon frequency.

Each unit includes direct current (DC)-to-alternating current (AC) converters, a surge protector and a DC-to-converter switch to provide DC power to the converters as well as to power up batteries for the generator and the backup power.

The dual-band systems feature two fiber FDMA and TDMA modems. A 10-megahertz reference is used for the low-noise block amplifier that is mounted on the feed. Another       10-megahertz reference is used for an L-band up converter. A mini spectrum analyzer helps users confirm that they are locked into the correct satellite.

A flat panel display and a keyboard trackball unit provide node management. The node manager hosts several commercial applications. Two Panasonic Toughbook node manager laptops allow operators to determine JNN status remotely.

These JNNs require a greater degree of specialization than have previous systems. Even contractors must be specialized, Maj. Douglas relates. For the first couple of   years, as it did during the early days of MSE fielding, the division will need to deploy with contractors to maintain the equipment.

Where troops previously could count on support from experts in a dedicated signal battalion, the new units of action will rely heavily on the division G-6 ensuring that the necessary training is achieved. “In some cases, we will be doing training over and over again,” he suggests.

Each signal company within a unit of action has a small network operations cell. This cell reports to the division network operations center under the G-6, which receives its priorities from the G-3.

A brigade must take on responsibilities that used to belong to the   G-6, Maj. Douglas relates. These include satellite access requests, frequency management, communications security management and circuit requests.

Dedicated Satellite System Supports Space Operations

Ensuring that the U.S. Army’s 101st Airborne Division’s satellite connectivity works is the purview of its space support office, which has its own system to help carry out the division’s mission and support operations. The Saturn terminal is a satellite transmission system that serves as a communications package, and it provides key capabilities that also serve overall division needs.

The whole Saturn system is transportable in two transit cases. It can use two types of satellite dishes—1.2 meters and 1.8 meters. In addition to benefiting from its portability, users can set up the system in a matter of minutes. It provides secret Internet protocol router network (SIPRNET) and nonsecure Internet protocol router network (NIPRNET) capability, and it provides additional bandwidth, complementing the Joint Network Node (JNN).

Maj. Tim Tubergen, a space support officer in the division, explains that the office’s proponency is the Army Space and Missile Defense Command. This element represents a transformational change for the division, as the office was not an integral part of the division during the first Iraq deployment. The office has five functional areas. One focuses on timing, including checking the global positioning system. The second involves working with the division’s G-6 office to ensure that it has no issues with satellite communications. Another key area is intelligence, surveillance and reconnaissance; the office can bring a large amount of imagery into the division from the Army Space and Missile Defense Command’s SpectralOperationsResourceCenter in Colorado Springs.

The major’s office also is active in early warning, and it works with missile defense personnel to ensure a correct architecture for that vital activity. It also can integrate the necessary communications for that activity.

The Saturn system provides entry to many of these functions. According to Maj. Tubergen, division personnel like it so much that his office is working to spread its benefits to the rest of the force. He explains that the Saturn system already has been incorporated into the mobile command group so that the commanding general has the communications package when he is mobile. Other efforts aim at increasing the capability for brigades and battalions.

Saturn uses the same satellite as does the JNN. However, Saturn’s and the JNN’s modems are different, and that prevents the two from tying together directly. If the heart of the Saturn system fails, users can tie into the Inmarsat system and operate through that commercial constellation.

One disadvantage Saturn has compared to JNN is that it can handle only a handful of subscribers. Maj. Tubergen offers that Saturn can work well for a forward entry unit. When the larger force reaches this unit’s location, the JNN would take over.

The major notes that the space support team is looking at land mobile radio, or LMR, on the move. G-4 Communications, Manchester, New Hampshire; Twisted Pair Solutions, Seattle, Washington; and Cisco Systems, San José, California, are working together to develop a system that brings single-channel telephony into the Internet protocol arena. The Army never could achieve that capability under MSE technologies, the major points out.

The division has a much greater single-channel capability, including satellite communications and high-frequency radio, than it did in its first deployment at the onset of the Iraq War. The doubling of this capability is allowing communicators to push it down to the company level or even to specialty platoons.


Web Resources
101st Airborne Division (Air Assault):
General Dynamics JNN: