To get where it wants to go and know what to do when it gets there, the U.S. Armyís 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 divisionís 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 divisionís 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 technology, which gives it a greater capability for tying into various other technologies in use.
The divisionís communications architecture comprises two hub nodes, 14 JNNs and 38 command post nodes for a 2/14/38 architecture. Maj. Bernd Kohler, USA, network engineer in the divisionís G-6, explains that this hub-centric, satellite-based architecture ensures that everyone is just ďone satellite hop away from the hub.Ē The hub would be located in a safe site to serve as the point of presence for Defense Information Systems Network (DISN) services and must provide access to the Global Information Grid from its sanctuary location.
This new architecture provides for high-bandwidth data service beyond push-to-talk. 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.
Each of the 14 JNNs takes the place of a node center and enables the functionality found in a small subscriber node. These JNNs provide switching functionality and subscriber functionality in a single assemblage.
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.
These JNNs also create one time division multiple access (TDMA) mesh per unit of action. The command post nodes and the hub are all 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 the hub using the full range of DISN services.
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 1 and Tier 2 security.
The system also provides a robust battlefield videoconferencing capability. 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 in 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. A VertexRSI 123T serves as the JNNís tracking system. Holzwarth explains that this unit simplifies tracking for the soldier running the JNN. That soldier merely needs to know the satelliteís 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. 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 mobile subscriber equipment 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.
The full version of this article is published in the September 2005 issue of SIGNAL
Magazine, in the mail to AFCEA members and subscribers September 1, 2005. For information about purchasing this issue, joining AFCEA
or subscribing to SIGNAL
, contact AFCEA Member Services