Tactical military communications.
Currently, the US Army is fielding its latest tactical information systems. Mobile Subscriber Equipment (MSE) is a fully digital area communications system providing secure voice, data and facsimile transmission for fixed and mobile users. It also is America's first tactical military cellular telephone system. As a completely digital system, MSE places tactical military communications a step ahead of the general public. The Single Channel Ground and Airborne Radio System (SINCGARS), built by ITT and General Dynamics, is a push-to-talk radio system providing secure voice, data and facsimile transmission for combat net users. In addition, it is the first frequency-hopping radio to be fielded to Army field units. The Maneuver Control System (MCS) is a computer-based [C.sup.2] tool. It is the first user of many Army Tactical Command and Control System (ATCCS) computers to be fielded to Army units. It utilizes the first tactical computer to be built using the Army's common hardware/software concept.
The MSE, SINCGARS, MCS and other new systems worked together to provide [C.sup.2] during Operation Desert Storm. This was their first large-scale test under fire, and the results were excellent. For the first time in the history of warfare, commanders were able to fight around the clock, processing and communicating information in real time from the National Command Authority to the foxhole.
These systems were born from operational concepts and requirements documents written at the US Army Signal Center, Fort Gordon, GA. At the Signal Center (the Army's tactical information systems think tank), soldiers and civilians continue to turn battlefield user requirements into systems. To keep pace with technology and to prepare for transition to the smaller but more lethal army of the next century - and its AirLand Operations doctrine - the Signal Center staff has developed an architecture and operational concept for the future and a plan for transition to that architecture. Called Battlefield Information Architecture, this new system will take the tactical army as far beyond the information systems of today as today's systems took us beyond the grease pencils and crank-to-ring telephones of 30 years ago.
TACTICAL COMMUNICATIONS DEVELOPMENTS
Albert James Meyer, an Army doctor, first conceived the idea of a separate, trained, professional military signal service. While serving as a medical officer in Texas in 1856, he proposed that the Army use his visual communications system, called wigwag. When the US Army adopted his system on June 21,1860, the Signal Corps was born, with Meyer as the first and only signal officer.(1) The Signal Corps has implemented many technological advances since Meyer's time.
In the 1960s our tactical telephones were crank-to-ring analog instruments interconnected by point-to-point circuits, and the signal unit owned, maintained and installed all phones. Included in the signal architecture were tactical teletypewriters, which could transmit and receive at 60 words per minute using 5-bit Baudot code. The tactical multichannel radio and cable systems that the Signal Corps developed featured pulse code modulation; the only tactical telephone switchboards used were manual. Tactical multichannel networks were organized much like the push-to-talk single-channel radio nets of the day - separate command operations and administration/logistics nets. These were highly centralized hub-type networks with only a minimum amount of alternate routing capability available. When fielded, manual switchboards were employed at the hubs so that calls could be switched by operators rather than being permanently installed point-to-point.
In 1970, tactical satellite communications (TACSATCOM) was moved from research and development, where it began in 1965, and became the responsibility of an Army Signal Detachment. Eventually, the multichannel TACSAT capability would drastically modify the overall networking architecture, but it was not until the late 1980s that satellite communications became an integral part of tactical communications networks.
The networking concept evolved to an area communications network featuring tandem automatic switchboards. This is the basic architecture resulting from the 1972 integrated tactical communications systems study.(2) It remains the architecture for the majority of Army units in the field today. Since then, however, every component has been replaced by newer technology. The US Army improved its area communications systems with the fielding of the Improved Army Tactical Area Communications System (IATACS). This family of shelterized multiplexer and transmission equipment and associated switching equipment provided automatic analog telephone circuit switching and point-to-point teletypewriter circuits.
In the late 1980s, the fielding of tri-service tactical (TRI-TAC) switchboard equipment began the transition from the old analog backbone and instruments to digital systems. TRI-TAC features hybrid (analog and digital) capabilities and sophisticated automatic circuit switching. TRI-TAC also includes a store and forward message switch. This message switch greatly improved record communications over the old point-to-point torn-tape-relay system. IATACS currently is being replaced at echelons corps and below by MSE and at echelons above corps by digital group multiplexing. Both fully digital systems are classified as Area Common User Systems (ACUS).
The early 1980s brought forth the greatest force modernization effort in the history of the Signal Corps. In 1985, GTE became the US member of a team to provide a non-developmental mobile subscriber system patterned after the French RITA system built by Thomson-CSF. With this system (MSE) came several new ideas in US tactical communications. First, subscribers now owned their own terminal instruments (e.g., phone, fax and message terminal). Second, it included a cellular radio-telephone system, and third, it employed flood search routing instead of deterministic routing for call establishment.
Flood searching is a technique whereby a switchboard initiating a call sends a call request to all of its neighbors. The neighbors do likewise. The first switch that can connect the call does so and the others are released. This makes MSE a much more survivable area communications system. The idea of user-owned and -operated equipment is termed the general purpose user concept. It saves on personnel costs.
MSE, an all-digital system, extends digital cellular telephone service to mobile subscribers. MSE retains the TRI-TAC message switch, but it replaces the TRI-TAC circuit switch at corps and the analog extension switch in divisions. The teletypewriter, which was part of a centralized telecommunications facility operated by signal soldiers, is being replaced today by a digital communications terminal (CT). The CT is user owned and operated and allows for writer-to-reader record communications.
The telephone instruments fielded in the 1980s use continuously variable slope delta modulation to digitize voice at the instrument. Hence, pulse code modulation signal multiplexing has become passe. Multiplexing is performed at the circuit switch and features both dipulse modulation (for compatibility with older equipment) and diphase modulation (to take advantage of the greater bandwidth capability of newer equipment). These technological domains carried over into MSE. With the fielding of MSE, these phones also become general purpose user equipment, and the supported soldiers carry them and connect them to junction boxes provided by signal units.
MSE telephones and the new generation of combat net radios (SINCGARS) both have ports for connection of data devices. This allows computers or facsimiles to use the systems. The SINCGARS radio, also a frequency-hopping radio, provides increased survivability of communications in a jamming environment. Additionally, it has a mean time between failure that is orders of magnitude better than the combat net radio family it replaces. The Army's Signal leadership recognized early on in the 1970s the potential utility of automation. The Military Computer Family Program was started, and special data networks in the communications architecture such as the Army Data Distribution System (ADDS) - employing TDMA spread spectrum technologies - were taking shape. Even 16 kb/sec data capability on SINCGARS in electronic-counter-countermeasures mode, fully encrypted, was planned. Technological breakthroughs in the industrial base with the introduction of the personal computer in the 1980s, however, offered the Army cost-effective alternatives for employment of computers supporting [C.sup.2].(1)
The Army's plan for automation, which had been underway since 1978, called for development of interactive tactical computer systems. Thus emerged a battlefield requirement for networking computers. Analog modems abounded and it became apparent that data users soon would contend with voice users for the network's limited bandwidth. As the Army developed data ports for its digital telephones, it began planning for a tactical packet network. This has since been contracted for, but was not to begin fielding until late 1991.
The ATCCS includes one more communication system: The Army Data Distribution System. This system, however, will not be fielded until the second half of this decade. ATCCS also includes five battlefield functional areas, each of which sponsors a Battlefield Automated System (BAS) and several subordinate automated systems. These will utilize tactical computers. The MCS is the BAS which is being fielded today. It is built on a common hardware computer platform using the UNIX operating system and, among other capabilities, provides electronic mapping and [C.sup.2] reporting. Maneuver control systems, personal computers and CTs generate a significant data traffic load, which must be carried by circuit switching or combat net radio until the tactical packet network (TPN) is fielded. This further exemplifies the need for the ADDS, SINCGARS data transport capabilities and the TPN, and the integration of each into a seamless network. This is the basis of integration efforts programmed for implementation in the mid- to late-1990s.
The Global Positioning System (GPS) satellite system also is now available to the American soldier. Thousands of GPS receivers were purchased in 1990 and fielded in Saudi Arabia. These receivers allow soldiers to accurately know their positions in latitude and longitude or military grid reference systems and to navigate from one location to another.
Network management has become more complex as communications equipment has become increasingly sophisticated. MSE is the first system fielded with its own automated network management system. The system control center allows signal unit operations personnel to more easily perform network planning and engineering and direct signal teams in the installation and reconfiguration of the network.
To summarize this brief history, a continuous development process has brought us to the mix of systems employed in support of Operation Desert Storm. The current mix includes sophisticated ACU communications, combat net radio and augmentation of both with satellite systems. It also includes [C.sup.2] computer systems and the GPS for navigation.
POST-COLD WAR STRATEGY
National strategy has changed and will continue to change to accommodate new realities of the post-Cold War world.(2) The US military and its associated [C.sup.2] structure must make corresponding adjustments to complement new roles and missions. While a hefty portion of the US military remains forward deployed at overseas bases, many of those units will be returned to the continental US, where they will become a home-stationed force. This force will be modularized to be more deployable to project US political will to any part of the globe, in any level of conflict. Future missions will range from refugee assistance and drug interdiction to high-intensity conflict. Accordingly, signal units must be designed and organized to be just as deployable and flexible as the forces they support.
Since US forces may be deployed to immature theaters (as in the case of the Gulf War), the signal unit supporting the force must be capable of providing essential [C.sup.2] capabilities from the very onset of the operation. It must then continue to expand and develop the overall signal support architecture as the theater matures. The methodology for accomplishing the above must reflect these needs. As a result, the Army's doctrine that supports national strategy also is evolving. Under the AirLand Operations concept, maneuver forces will be designed and organized to be more lethal, mobile, tailorable and flexible. These forces must be capable of rapid movement over great distances on a vastly expanded battlefield. Today's signal support system, which is oriented to grid coverage over a fixed piece of terrain and only minimally integrated, will not suffice in the future.
Future doctrine envisions virtually all operations to be joint (multiservice) and many to be combined (multinational). Information systems will there-fore require interfaces to and interoperability with one other and the host-nation information systems.
The new AirLand Operations doctrine is expected to be implemented in the period 1994-2004. Rapid expansion of information requirements and the trend toward high mobility, flexibility and deployability are expected to continue well beyond that time. The strategy for implementing the new Battlefield Information Architecture calls for a near-, mid- and long-term effort. Each period is important. The long-term look takes on special significance since it represents the objective architecture to which the preceding efforts must build. In the future, signal support will be founded on an integrated Battlefield Information Architecture (BIA). The components of this BIA will be multi-functional, modular, tailorable and flexible - in contrast to today's more rigid architecture, each designed to provide various types of service to users at different echelons.
The future's system must be coherent, integrated architecture which provides multiple services to users. This Open Distributed Processing/Intelligent Network will make the maximum use of national and international standards and protocols and will be an integral part of joint, combined and commercial systems. The near term is ultimately important since today's funding decisions determine tomorrow's actual architecture. The following describes the near-term effort.
The fundamental goals of near-term efforts at the Signal Center are to complete the planned ATCCS architecture; to enhance the integration of the systems composing that architecture; to prepare for and maintain compatibility with developments in the strategic environment, sustaining base and tactical user community; and to begin development of critical new systems which will bring us forward to the 21st century in the direction of the objective system.
To lay out the strategy for the accomplishment of these goals, the Signal Center formed an architecture task force in November 1990. The task force developed the concept for the objective system and organized a plan for the implementation of its strategy. This plan, described briefly below, affects nearly every ongoing developmental effort. It also necessitates cooperation among the Signal Center, the technology base, materiel developers and industry. The framework for the plan chosen by the task force is based on the composition of ATCCS.(3) First, it deals with communication systems - ACUS, combat net radio (CNR) and ADDS. Second, it adds range extension capabilities as required for AirLand Operations by each of the communication systems. Third, it deals with automated systems - the computers which drive BASs. Fourth, it includes control (of theater tactical communications systems) and management of the information resources attached to them. Fifth, it deals with information security as required by all communications systems and information resources.
The main goal in ACU's developments is to complete the programmed architecture and improve voice and data service availability. To do this, we must provide the same functionality in tactical systems at echelons above corps as is being fielded for echelons corps and below. This includes flood search call routing and a seamless TPN. The tactical record traffic system must be upgraded through a rebuild program for message switches, and we must begin to conceptualize a system for providing packet-based messaging to tactical subscribers. The intent is to eventually extend the Defense Message System to the tactical world. To enable this, we must develop a multi-level secure system. Also, we must improve worldwide access to tactical users through exploitation of commercially available satellites. Finally, we must conceptualize the employment of next-generation equipment such as surrogate satellite and multiband radio (MBR) technologies and capabilities essential for extended range and bandwidths for the late 1990s' support of AirLand Operations.
The main goal in CNR developments is to complete fielding of SINCGARS to the active Army. The second goal is to accomplish a block capability upgrade to SINCGARS, field it to the active Army and use displaced SINCGARS radios to eliminate the old generation of equipment from the Army inventory. The upgrade will include improvements to the user-friendliness of the radio, an embedded GPS reception capability, improved data handling and automatic net radio interface to ACUS for both voice and packet data. The third goal is to satisfy the existing requirements for more HF radios. A fourth goal is the development and demonstration of MBR technology providing a single-unit radio band from HF to EHF. This MBR technology, first applied as a mid-term replacement for combat net radios, will be built with groups of common modules which can be software configured to generate multiple simultaneous waveforms in any frequency band from HF to EHF. These common modules will be employed in a family of chassis including hand-held, manpacked, small vehicular (including ground, water and air vehicles) and shelter-mounted versions. The programmable nature of this radio will potentially make it an eventual replacement for all of the Army's transmission systems. It will further set the stage for long-term MBR development into the optical spectrum (above THz).
The immediate goal of ADDS developments is to demonstrate the viability of the programmed system. Following this, the goal is to accomplish the fielding of a viable data-distribution architecture within its reduced funding constraints. The ADDS system fielded must be integrable with data services provided by ACUS and CNR.
The goal in range extension development is to improve an ability to support AirLand operations for the near term and set the baseline for long-term initiatives supporting Army 21 concepts (2020). This will involve enhancement of current capabilities (satellite) and extensive R&D efforts to develop new capabilities. To do this, we need to institutionalize our concept for the employment of range extension systems, followed by the development, validation and implementation of corresponding requirements documents. Plans and actions already are in place to do just this for new technologies such as the MILSTAR satellite and unmanned aerial and ground vehicles. Also, concept formulation and action plans are taking shape to develop the ability to use or augment host-nation and US commercial systems. Consideration must be given to the employment of new technologies such as multiple path beyond-line-of-sight systems and the multiband radio as range extension assets.
The goal in automation is to field user-friendly automation devices and software to enhance productivity. This necessitates the adoption of an open-systems architecture. It also means better (graphic) user interfaces, artificial intelligence, built-in test and diagnostics, embedded training and the investigation of hands-free operation through voice interaction. Further, enabling [C.sup.2] on the move forces the development of wireless LAN capability.
Communications systems must be able to support multimedia services (including video), which will further drive the need to provide more bandwidth. Conversely, however, applications must ensure they optimize their use of the limited bandwidth available. This means the employment of efficient data-transfer protocols and data compression and the redoubling of efforts toward reduction of functional layering, elimination of nonessential processing and the transmission of necessary information only. Correspondingly, a greater reliance on modeling and simulation will ensue in order to analyze the adequacy of supporting systems, but equally important will be the need for better modeling capabilities and a better system for collection of information to be modeled.
The goal in control is to develop an integrated systems control capability for strategic, theater and tactical echelons that underwrites total interoperability. This necessitates the development of a system capable of managing all communications and information resources in the theater, to include conceptualization of network management features and procedures that will employ multiband radios in all the various possible modes.
The goal in information security is to field improved security systems. These must be more user friendly and reduce the operational overhead of encryption key management. Critical technologies under development for securing the ACUS include Firefly (public keying, as in the STU-III telephone) for the circuit-switched network and multilevel security (MLS) for the soon-to-be-fielded Tactical Packet Network. The critical system which will decentralize and automate key management is the Army Key Management System. Simultaneous development of MLS capabilities for all types of terminal equipment is essential, as is the achievement of a trusted computing base through development of an MLS operating system. Also necessary is conceptualization of the way security will be provided to systems based on future technologies like the multiband radio. Above all, the systems listed above must interoperate and mutually support one another in their employment on the battlefield. Their development must set us on the glide-path to the objective system.
We must meld, and in some cases modify, current actions and programs to produce the desired outcome. The near- and mid-term strategies developed by the Signal Center will effectively synergize those efforts. Additionally, the military must further explore the use of civil/reserve resources to satisfy wartime [C.sup.3] needs. A great many of those commercial resources (e.g., commercial satellites, undersea cables, state-of-the-art terminal devices, etc.) were used during the Gulf War. What is needed now is a program similar to the Air Force's civil reserve air fleet, which allows wartime use of commercial aircraft, for signal support resources. These efforts continue to be actively pursued as a logical progression to the Army's objective Battlefield Information Architecture.(2)
1. K. Coker and C. Stokes, "A Concise History of the US Army Signal Corps," Office of the Command Historian, US Army Signal Center and Fort Gordon, Fort Gordon, GA, Feb., 1991.
2. BG D.J. Kelley, COL W.M. Guerra and CPT J.A. Brendler, "Future Tactical Communications Systems," MILCOM '91, Fort Gordon, GA, July 1991.
3. PT J. A. Brendler, Signal Center Briefing, "Battlefield Information Architecture Near-, Mid- and Far-Term," Fort Gordon, GA, May 13, 1991.
CPT Joseph A. Brendler was the commander of Company C, 50th Signal Battalion (Airborne), Fort Bragg, NC, when this was written. He is presently stationed in Germany.
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|Author:||Brender, Joseph A.|
|Publication:||Journal of Electronic Defense|
|Date:||Jan 1, 1995|
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