'Data-Centric' Army Wants Next-Generation Tactical Net.

• Author: Erwin, Sandra I.
• Position: Development of wireless communication systems for combat units

A blend of advanced commercial and military wireless communications technologies is at the core of the U.S. Army's effort to give dispersed lower-echelon forces--which are constantly on the move--capabilities to send and receive massive amounts of data, video and voice messages at a faster clip and with greater reliability than is now possible.

Projects currently underway by Army and commercial organizations are pursuing more compact, agile and capable communications systems that will be required by combat units within the next 10 years.

Army researchers and industry suppliers believe that the performance of today's tactical communications systems could be improved significantly, given the advent of technologies such as digital multi-band radios and extended-range network capabilities. These experts also note, however, that communications networks at the brigade-and-below levels remain constrained by "legacy" radios--which are limited to a single waveform (a form of transmission) or to a single bandwidth, and have low data transmission speeds.

For several years, the Army has been working to "digitize" combat units. This essentially means that each vehicle in a division, for example, is part of a digital network, called the "tactical internet." Each vehicle has a computer terminal, so it can receive updates on friendly and enemy force locations, command and control, and fire support data, all of which are routed over the network.

Today's tactical internet is made up of several existing radio systems, each of which performs unique functions. The standard combat net radio is the single channel ground and airborne radio system (SINCGARS). The vehicle-mounted wideband radio used for data distribution is the enhanced position location reporting system (EPLRS). At the tactical operations center, commanders rely on the mobile subscriber equipment's tactical packet network, and the near-term data radio (NTDR).

Those disparate communications systems are connected via Internet routers that use the IP, or Internet protocol, the standard adopted by the commercial Internet and corporate intranets for transporting data packets.

In the tactical internet, vehicle-mounted computer terminals--equipped with the Force XXI battle command brigade-and-below software (FBCB2)--display a common picture of the battlefield.

Communication Needs

The future communication needs of forces on the move--the units at the brigade level and below--currently ate the focus of an Army project called Mosaic (multifunction al, on-the-move, secure, adaptive, integrated communications).

The current tactical internet cannot achieve the connectivity or high speed of transmission the Army wants for the future, so the next step is to build a "next-generation tactical internet," said David Keetley, director of space and terrestrial communications at the U.S. Army's Communications and Electronics Command (CECOM).

"The next-generation internet involves entirely new technology," said Keetley in an interview.

The backbone of the next-generation tactical internet will be a digital, programmable radio called JTRS, for joint tactical radio system. A JTRS, program office was set up to spearhead this effort. The plan is to field a family of radios, for use by all military services. Because JTRS will have an open systems architecture, each service or unit can program its radios for a specific function (handheld manpack, air-to-ground, air-to-air), to operate in a specific frequency band (very high frequency VHF, high frequency HF, ultra-high frequency UHF) and to receive and transmit dozens of different waveforms.

For the Army, two of those waveforms will be SINCGARS and EPRLS. The Army's large investment in these two legacy radios (about 250,000 SINCGARS and 8,000 EPRLS) means they will be...