8
Research Objectives

This chapter proposes 20 strategic research objectives that are critical to future energy sufficiency on the battlefield. It also highlights particular steps that should be taken to fulfill those objectives. For planning purposes, the chapter provides implementation guidelines based on the committee's assessments of commercial and military activities in the technology areas addressed in this study.

ENERGY SOURCES AND SYSTEMS

In the near term, the Army's pursuit of better energy sources for the dismounted soldier will continue to depend on the development of commercially viable sources with higher specific energy; these energy sources must be safe, rechargeable, lightweight, undetectable, reliable, adaptable to military configurations, and supported by domestic manufacturers. All of these criteria cannot be met with batteries. Therefore, the Army's research should focus on small, lightweight, intermediate-store fueled systems. The committee also believes that research in human-powered systems has the potential to meet the level of autonomy that will be necessary for dismounted soldiers in the Army After Next (after 2015).

Rechargeable Batteries

Improvements on the order of a factor of two or more can be achieved by advances in processing technology, active material composition morphology, reinforcing components, electrolytes, and components with limited cycle life and recharging rates, such as separators. Rechargeable batteries have significant logistic advantages for the Army, but their specific energy is only about half that of equivalent primary batteries. An immediate goal for the Army is to develop a rechargeable battery with specific energy equivalent to the best primary battery, about 200 Wh/kg. Chargers and state-of-charge devices, which are relatively inexpensive, have a major effect on battery performance and safety. The main goal of research in this area should be to incorporate new and improved circuit



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Energy-Efficient Technologies for the Dismounted Soldier 8 Research Objectives This chapter proposes 20 strategic research objectives that are critical to future energy sufficiency on the battlefield. It also highlights particular steps that should be taken to fulfill those objectives. For planning purposes, the chapter provides implementation guidelines based on the committee's assessments of commercial and military activities in the technology areas addressed in this study. ENERGY SOURCES AND SYSTEMS In the near term, the Army's pursuit of better energy sources for the dismounted soldier will continue to depend on the development of commercially viable sources with higher specific energy; these energy sources must be safe, rechargeable, lightweight, undetectable, reliable, adaptable to military configurations, and supported by domestic manufacturers. All of these criteria cannot be met with batteries. Therefore, the Army's research should focus on small, lightweight, intermediate-store fueled systems. The committee also believes that research in human-powered systems has the potential to meet the level of autonomy that will be necessary for dismounted soldiers in the Army After Next (after 2015). Rechargeable Batteries Improvements on the order of a factor of two or more can be achieved by advances in processing technology, active material composition morphology, reinforcing components, electrolytes, and components with limited cycle life and recharging rates, such as separators. Rechargeable batteries have significant logistic advantages for the Army, but their specific energy is only about half that of equivalent primary batteries. An immediate goal for the Army is to develop a rechargeable battery with specific energy equivalent to the best primary battery, about 200 Wh/kg. Chargers and state-of-charge devices, which are relatively inexpensive, have a major effect on battery performance and safety. The main goal of research in this area should be to incorporate new and improved circuit

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Energy-Efficient Technologies for the Dismounted Soldier components as they become available. Advances in charging methods can provide for more rapid recharging, longer cycle life, and higher performance. Chargers and State-of-Charge Devices These relatively inexpensive electronic components have a major effect on battery performance and safety. The Army must maintain the option of incorporating improved circuit components as they become available. Advanced charging methods can provide rapid recharging, longer cycle life, and higher performance. Aqueous Systems Significant improvements in specific energy, specific power, and cycle life can be achieved by optimizing the structure and particle size of reactant materials. Other areas of investigation of interest to the Army include: low cost methods for active material preparation (candidates include xerogel and aerogel methods; nanostructural materials; and optimized heat treatments) improved separators for better electrolyte wicking and retention for longer cycle life substrates for electrodes that can act as structural materials, current collectors, and bipolar sheets seals to prevent leaks, allowing for maintenance-free cells advanced electrolyte systems, new compositions, and gelled electrolytes   Lithium Systems Research areas of interest to the Army for rechargeable lithium cells include: overcharge and discharge tolerance via cell design and charge control improved positive electrode materials and preparation methods for long cycle life, low cost, and environmental acceptability electrolytes with greater stability, improved conductivity (both polymer and liquid), and nonflammability management of the Li/electrolyte interface and film lower cost separators electrochemical couples of higher specific energy  

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Energy-Efficient Technologies for the Dismounted Soldier Fuel Cells Fueled energy sources offer the most potential for meeting the needs of the dismounted soldier. The following are the key research areas: more efficient methods of storing and/or generating hydrogen fuel reducing operating pressures to near atmospheric pressure improving the carbon monoxide tolerance of systems using reformed fuels reducing the cost of bipolar plates/flow fields reducing system complexity improving water management reducing the cost of proton exchange membranes improving catalysts for direct methanol fuel cells reducing the rate of methanol crossover increasing specific power to higher than 100 W/kg for small (< 100 W) systems at atmospheric pressure   Advanced Fueled Systems Advanced fueled systems, including thermophotovoltaic systems, microturbines, and hybrid systems, will enable the revolutionary increases in dismounted soldier combat capabilities for the Army After Next. Of these capabilities, microclimate cooling will continue to be the most demanding (in terms of energy) of all of the capabilities studied by the panel. Successful development of a microclimate energy source will depend on the mission profile, the size of the energy storage unit needed for the mission, and the efficiency with which the stored energy can be converted to active cooling. Continuous high level cooling for missions longer than a few days will clearly require massive energy sources, i.e., high specific energy fueled systems with power levels above 150 W and several kWh of stored energy. Innovative, efficient conversion technologies for converting stored energy to active cooling will also be necessary. Microturbines The most revolutionary, and possibly the highest risk, advance proposed for compact power systems based on rotating machinery is for miniaturized turbines driven by combustion or high pressure gases. Key research areas include: liquid combustion in small systems active noise cancellation microturbine fabrication miniature electrostatic generators thermal signature mitigation  

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Energy-Efficient Technologies for the Dismounted Soldier Thermophotovoltaic Systems The potential for TPV (thermophotovoltaic) power systems has already been demonstrated. The next step is to build prototype systems for evaluation and then focus research on correcting flaws and inadequacies. Several R&D topics must be thoroughly investigated before optimized TPV systems can be developed. The most important are: liquid fuel combustion in small systems strong robust radiators bandgap tailoring in photovoltaic materials and devices design of cavity structures, including emitters, filters, cell arrays, and coolant/recuperator schemes high temperature recuperators prototype systems   The necessary fabrication technology must be established concurrent with these demonstrations and experiments. Research should also focus on characterizing the capability of each component within the framework of the application for the dismounted soldier. The successful application of TPV technology must result in weight savings, cost savings, added capability, and reliability. At the component level, the priorities are: demonstration of a diesel burner/recuperator/emitter in an integrated unit development of optimized, affordable photovoltaic cells development of the optical cavity consisting of emitter, photocell, and filter as an integrated unit   Hybrid Systems Numerous laboratory demonstrations of hybrid systems that would be applicable to the dismounted soldier have been made. Pulsed power techniques have been extensively employed in the high power regime; however, no field tests have been done to determine the utility of this approach to human-portable power. To optimize the design, it will be necessary to have information on the power demand time history for a variety of mission profiles. Based on this data, a hybrid system could be designed for a worst case scenario that maximizes available energy. The success of hybrid systems depends on the successful development of each component in the hybrid power train. The key issues are developmental. They include the following: development of computer models for predicting hybrid system performance as a function of mission profile  

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Energy-Efficient Technologies for the Dismounted Soldier development of laboratory prototypes reliable field data on which to base energy utilization profiles of the various soldier subsystems   Human-Powered Systems Human-powered systems will become increasingly important as the duration of operations by the dismounted soldier is extended. Converting the energy associated with body motion to electricity would radically improve the dismounted soldier's capabilities. To exploit the potential of human-powered systems, the following research areas should be explored: efficient lightweight intermediate storage units analysis of the motions involved in routine tasks and coupling unobtrusive converters to this motion laboratory prototypes employing small electromechanical and piezoelectric converters   LOW POWER ELECTRONICS AND DESIGN Technologies in low power electronics and design have benefited greatly from the incentives of the commercial marketplace. Army systems, particularly those on which the future dismounted soldier will depend, have not generally benefited from commercial development. The research objectives described below are particularly relevant to meeting the Army's needs. Circuit Design Tools for Minimizing Power Requirements The commercial driving forces behind CAD (computer-aided design) tools for highly complex circuits have been improved circuit packing density, higher performance circuits, self-testing circuit modules, and an improved automated design process. Commercial developments in low power electronics have focused on silicon efficiency (area and performance) but not on reducing energy consumption. The Army needs new design tools that include energy efficiency as a major goal. These tools should focus on determining the energy used at each stage of the design process and making circuit design and layout decisions that would minimize power requirements. Each parameter that affects power should be considered for each step in the circuit design and implementation, from logic to circuit to device.

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Energy-Efficient Technologies for the Dismounted Soldier Architectural Design Level Tools At the architectural design level, tools should allow the designer to explore, evaluate, compare, and optimize energy dissipation alternatives early in the design process. At this level, switching activity, the required operating voltage level for each circuit block, and the capacitance of each circuit node should all be considered for their affect on power requirements. Power-down or ''sleep" circuits to minimize the standby power required for inactive circuits can also be incorporated at this level. Energy savings can also be obtained by optimizing the instruction set or using a hardware module to implement a specific data path to execute a specific instruction. Packaging Techniques for Minimizing Interconnects Significant energy savings can be made by choosing the proper package design for integrated circuit input and output connections. The number of connections should be kept to a minimum to reduce the number of energy-consuming drivers; the capacitance associated with each interconnect node should also be minimized. Although the use of multichip modules will be beneficial, the Army should use packaging techniques with low interconnect capacitance. Submicron Lithography The semiconductor industry is committed to achieving the goals of the NTRS (National Technology Roadmap for Semiconductors) and has been making large investments each year in pursuit of those goals. As the apparent fundamental limits are approached, even larger investments in submicron lithography and advanced fabrication techniques that cannot be funded solely through commercial sales will be necessary. For the Army to keep pace with commercial progress in low power semiconductor technology, it must monitor and support advances in technology and be sensitive to industry's limitations. Optimizing Device Design At the device level, individual transistor designs can be optimized to reduce the power required. Clever transistor geometry layout can be used, for example, as well as technologies with low leakage currents. Device current ratios and threshold voltages can also be optimized to reduce power. Leakage current can be minimized by using SOI (silicon on insulator) technologies, including silicon on sapphire with thin silicon conducting layers. Research in this area would extend the work supported by DARPA (Defense Advanced Research Projects Agency) on low power circuits on SOI.

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Energy-Efficient Technologies for the Dismounted Soldier Design Methodologies for Army "Systems on a Chip" By the year 2010, commercial progress in fabrication technology will yield an increase of 100 times more transistors on a single integrated circuit. This advance would permit all of the functions that are planned for the Land Warrior system to be easily implemented on a single chip. In fact, capabilities far beyond Land Warrior's computation and communication capabilities could be implemented, including support for low energy networking, protocols, signal processing, and analog capability for interfacing and processing data from various sensors. Additional computation circuitry to compress data, which would reduce the power required for data transmission, would also be possible. This high level of integration will allow architectures that reduce energy consumption and size. The Army should support research on customizing design methodologies to reduce total energy consumption. The application of board level design methodology to monolithic chips will be critical. This will mean integrating modules from different suppliers into a single circuit (just as chips from different suppliers are integrated onto the boards used in Army electronic systems today). Standard interfaces for these modules must be defined, as well as methods of testing, technology compatibilities, and methods of verification that are far beyond present day capabilities. COMMUNICATIONS, COMPUTERS, DISPLAYS, AND SENSORS In general, the Army must be prepared to embrace commercial electronics technologies that have the potential for improving energy-efficiency by factors of 10 to 50 for a given level of performance. In addition to making progress in microelectronics circuit design, industry is working at the product level to use lower supply voltages and to optimize systems architectures with more parallel processing and more efficient distribution of functions between hardware and software. With ASIC (application-specific integrated circuit) systems-on-a-chip technology, it is possible to customize energy efficient systems even for the relatively small production runs needed for dismounted soldier systems. Key research objectives are described in the following subsections. Terminal Equipment Architectures for Optimizing Energy Consumption The Army should capitalize on the DARPA program to develop a low power multimedia terminal (discussed in Chapter 5). This program includes optimizing the communications architecture, processing hardware, and device architecture for a military terminal. The goal is to require only 5 mW of power, even during constant operation. This research merges the communications and computing functions.

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Energy-Efficient Technologies for the Dismounted Soldier Component and Human-Computer Interfaces Army-sponsored research should focus on developing embedded, dedicated computer systems, rather than adapting general-purpose personal computers. Ideally, each sensor or subsystem should have its own processor and wireless transceiver, and user level programming should be minimized. Designing human interfaces should be given serious attention because efficiency depends on simplicity and clarity. To minimize the number of human inputs, the soldier's tasks must be modeled and interfaces closely matched to tasks. The range of available input interfaces is growing; within a year or two it will include not only the keyboard and mouse on an iconic desk top, but also voice and handwriting recognition, position sensing, and eyeball tracking. Output options will include speech synthesis and heads-up displays. The processing requirements (and thus the energy consumption) of various output and input methods will vary over several orders of magnitude. Particular research challenges include the following: Matching capability with applications. The current thinking is that the highest performance capability is the most desirable. However, this capability is often unnecessary, and enhancements, such as full color graphics, require substantial resources. High performance enhancements may actually decrease ease of use by generating information overload for the user. For example, the Marine Corps Hunter-Warrior field exercise provided forward observers with hand-held personal digital assistants. Almost 60 percent of the messages were position situation reports that required only short textual messages (Seaton, 1997). Systems design should focus on the most effective means of accessing information and resist the temptation to provide extra capabilities simply because they are available. Input/output modalities. Modalities that mimic the input/output capabilities of the human brain have been the subject of computer science research for decades, but they are still inaccurate and difficult to use. Many require extensive training, and inaccuracies often frustrate users. In addition, most of these modalities require extensive computing resources that increase energy consumption and weight. User interface models. Appropriate metaphors for providing mobile access to information (that is, the next "desk top" or "spreadsheet") typically take more than a decade to develop because they require extensive experimentation and because different applications or information types may require different metaphors. Quick methodology for evaluating interfaces. Current approaches to evaluating a human-computer interface require elaborate procedures and scores of subjects. Evaluations may take months, and they cannot be done while the interface is being designed. New methodologies should focus on reducing human errors and frustration.  

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Energy-Efficient Technologies for the Dismounted Soldier Ultra Low Power Displays and Sensors Lower energy consumption by display subassemblies can be achieved by long-term R&D. First, system level design trade-offs should be introduced early in the display development stage. Considering the reduction in energy consumption that can be achieved by eliminating the analog-to-digital conversion step, the necessity for the digital format should be investigated, especially for functional enhancements that are planned downstream. The wide field of view of the virtual retinal displays will mean meeting the mechanical challenges of the scanning function. The human-display interface format must be optimized for maximum situational awareness. Data collection and simulation modeling are also needed. Further development of MEMS (microelectromechanical systems) technology for microbolometers will improve the performance of uncooled infrared sensors. This will mean higher resolution of the imager and minimizing the temperature extremes over which control must be maintained. The energy efficiency of the sensors and displays could be improved through development of an optical fiber collector net to feed data to a central detector processor. Similar architectures might be used to support electronic sensors for optical energy, radio frequency energy, chemical agents, or radioactivity. Multimodal and Adaptive Communication Circuits To achieve the flexibility and energy reductions in radio modem circuits that will be possible in future integrated circuit technology, the Army will require designs that allow analog radio frequency circuitry to coexist on the same circuit as digital processing optimized for low power. This capability is necessary because radio architectures that are mostly digital will make it possible to reconfigure or reprogram the digital portions of the circuit to adapt to different modes of operation. Army radios could therefore use communication system architectures that adapt to the environments in which they are used and to the tasks for which they are being used. For example, a radio system that is energy optimized for voice transmission among members of a squad in a rural environment will be quite different from one that is emulating a commercial protocol to exploit existing infrastructure in an urban setting. It would be highly desirable to have a single portable radio that could be adapted to as low an energy level as possible for various tasks and environments. Evolution of Hardware and Software As fabrication technology improves, the energy penalty for implementing a given communications or computation function in a flexible software solution rather than in a dedicated architecture will decrease. To keep from lagging behind

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Energy-Efficient Technologies for the Dismounted Soldier the commercial technology, the Army must continually update computation and communication circuits. Updating will require a modular, upgradeable architecture as well as a design methodology that can accommodate the energy trade-offs between dedicated hardware solutions and software implementations. In addition, software compilers and operating systems that minimize energy are needed for the software-enabled parts of these systems, which also must allow more energy-efficient hardware to be used without costly software rewrites. NETWORKS, PROTOCOLS, AND OPERATIONS Key research objectives to support the Army's goals for energy-efficient networks, protocols, and operations are described below. Wireless Battlefield Communications Network The Army should pursue research aimed at adapting commercial cellular and personal communication system networks and technologies to the needs of future soldier systems. As explained in Chapter 6, radio networks and protocols at the soldier level require peer-to-peer architectures for low latency connectivity and, simultaneously, require hierarchical architectures to meet power concerns and the capability to use COTS (commercial off-the-shelf) technology. The international (hierarchical) GSM (Global System Mobile) standard now offers low cost, low energy consumption, low latency, and is adaptable for covertness and security. A hybrid wireless network architecture that provides "virtual" peer-to-peer communication with a hierarchical physical architecture based on GSM should be adapted and optimized for the dismounted soldier. Extending the Range of the Dismounted Soldier The Army's wide range of communications requirements dictates that energy-efficient wireless networks be optimized for specific environments, which will require a wide range of radio interfaces. Terrestrial and satellite-based networks can be part of the overall communications pathway to and from the dismounted soldier. Specific research objectives in this area include: creation of dynamic network management protocols for multihop, multiply connected networks incorporation of signal processing algorithms to cancel or avoid interference and jamming investigation of architectures involving satellite or other aerial repeater platforms  

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Energy-Efficient Technologies for the Dismounted Soldier Sensors and Software for Power Management Much of the power requirement for Land Warrior and successor systems will be attributable to subsystems listening for relatively infrequent stimuli from inputs. Protocols and networks that support powering downstream subsystems only when necessary can reduce power requirements. This "sleep mode" concept is also applicable to computing systems and wireless systems. Automatic or soldier-mediated control of high power functions will conserve energy that can be used to transmit images and video. Models for Optimizing Energy Efficiency Energy efficiency directly affects the combat effectiveness of the dismounted soldier by determining the weight, bulk, data-handling capacity, and stealth characteristics of battlefield equipment. Simulation models that incorporate models of soldier effectiveness and behavior will make possible trade-offs among localized computation, distributed databases, information dissemination patterns, and soldier operational doctrine to optimize the design of dismounted soldier systems. Research areas include: cost/benefit (energy consumption/combat effectiveness) studies of high rate information flow on the battlefield system level simulations that incorporate soldier behaviors and computation/communications trade-offs on the battlefield to evaluate power discipline (both automated and manual) and to optimize overall energy consumption   Propagation Characteristics and Antenna Design Energy for radio transmission will dominate power requirements for the dismounted soldier of the future. The complex radio propagation environment is heavily influenced by topography, foliage, precipitation, buildings, and the antenna heights. These influences change significantly at the high frequencies that will be used to support the increased information flow to and from dismounted soldiers. The performance of advanced antenna technologies, such as phased arrays, and the signal processing and control complexity needed to attain a given level of performance depend largely on the characteristics of the radio path. Propagation measurements, modeling, and research on antenna technology are needed to characterize and quantify interactions of the environment and antennas.

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Energy-Efficient Technologies for the Dismounted Soldier IMPLEMENTATION GUIDELINES The Army can count on several research objectives being met by commercial companies working for commercial ends. Objectives with specific military applications will require special attention by the Army to encourage commercial interest and, in some cases, will require Army investment. Table 8-1 characterizes the 20 strategic research objectives identified by the committee. Near-term objectives are those for which research is urgently required to achieve goals set for Land Warrior systems on the digitized battlefield. Far-term objectives are those required to achieve a goal of energy sufficiency for the dismounted soldier in the Army After Next (after 2015). The column headed "Commercial Research Leverage" refers to objectives that will benefit from commercial R&D. The column headed Military-Specific Application refers to objectives unlikely to be pursued by commercial companies. Of the 20 objectives identified, the committee believes that three research objectives have the most potential for balancing future energy demands and for increasing combat effectiveness by meeting power requirements of the dismounted soldier. These deserve immediate emphasis: wireless battlefield communications network models for optimizing energy efficiency advanced fueled systems   Wireless Battlefield Communications Network As communications come to dominate the energy consumption of systems for the dismounted soldier, the creation of a virtual peer-to-peer architecture, as discussed in Chapter 6, will become increasingly important. Implementation of virtual peer-to-peer architecture will require much more than the straightforward adaptation of commercial technology. Although coding standards, some communications protocols, and a basic architecture might be borrowed from the wireless telephone and pager industry, the complexity of the Army's network will be heightened by the need for optimum reliability in extremely harsh communications environments characterized by high levels of interference, jamming, and unpredictable transmission paths. Building a network that can continue to operate when one or more nodes have been destroyed will require protocols that are not available commercially. The use of terrestrial or aerial repeaters to enable the transmission of digital data will require the development of complex and secure system software. Optimizing the distribution of information on the battlefield to eliminate unnecessary wireless traffic will require multidisciplinary thinking by experts in military doctrine, communications

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Energy-Efficient Technologies for the Dismounted Soldier TABLE 8-1 Research Objectives   Near Term Far Term Commercial Research Lever Military-Specific Applications Energy Sources and Systems         Rechargeable batteries X   X X Fuel cells X     X Advanced fueled systemsa   X   X Human-powered systems   X   X Low Power Electronics and Design         Design tools for minimizing power consumption X   X X Architectural level design tools X   X X Packaging to minimize interconnects   X X X Submicron lithography   X X   Optimizing device design   X X   Design methodologies for Army "systems on a chip"   X X   Communications, Computers, Displays, and Sensors Terminal equipment architectures X   X X Component and human computer interfaces   X X X Ultra-low power displays and sensors   X   X Multimodal and adaptive communication circuits X   X   Evolution of hardware and software   X X   Networks, Protocols, and Operations Wireless battlefield communications networka   X   X Extending range of the dismounted soldier   X X X Sensors and software for power management X   X X Models for optimizing energy efficiencya X X X X Propagation characteristics and antenna design   X   X a Objectives with highest potential. technology, speech and image coding, information presentation, and database management. The goal is to minimize energy consumption and electronic signatures while maximizing the combat soldier's effectiveness. The Army should begin by assessing the state of the art of commercial communications technology. Simulations should be conducted of prospective communications architectures. The Army should not try to develop a completely

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Energy-Efficient Technologies for the Dismounted Soldier separate communications system; instead, it should share the most costly aspects of the system, such as the development of UAV repeaters or steerable antenna technology, with the other military services, government agencies, and defense and commercial electronics industries. Cost and timeliness should be central considerations. Models for Optimizing Energy Efficiency The energy use of Land Warrior and successor systems for the dismounted soldier will depend on a host of variables, including electronic device technology, the characteristics of energy sources, processing algorithms, the communications architecture and protocols, sensors, and tactical and operational doctrine. Integrating this complex system and ensuring the greatest benefit per unit of energy consumption will require high fidelity models of the soldier's activities on the battlefield. These models will be invaluable planning aids and could provide an important check on the practicality of advanced doctrinal concepts. The first step in devising a model should be to place instruments aboard prototype systems during tests and maneuvers to obtain an accurate picture of how the system is used. The instruments should measure the patterns of use of all energy-consuming subsystems, the functions of energy supplies, and the duty cycles of weapons and other equipment for a variety of mission types. Wireless communications, which promise to account for the major share of energy used, should be measured in detail. The physical load of ammunition, weapons, equipment, and food should be measured at intervals. As the model is optimized, it could be used to determine trade-offs between an energy consuming subsystem, such as communications, and other equipment subsystems, such as the Land Warrior science and technology insertion candidates and other proposed capabilities. The model could help to measure and forecast progress in technology and could ultimately be used to derive dynamic estimates of optimal equipment loads and capabilities for various mission types. Advanced Fueled Systems The development of a hybrid system with fueled primary store has potential to revolutionize warfare as much or more than information technologies. Advanced fueled systems, including microturboalternators, TPVs (thermophoto-voltaics), and fueled system hybrids, will not only minimize the soldier's dependence on logistics, but will also provide power for any new electronics that are developed to enhance lethality or mobility in the interim. Because communication needs predominate, it is extremely important that development of a hybrid system matched to soldier communications needs, including low probability of detection, proceed in conjunction with the adaptation of wireless communication technologies to the battlefield.

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Energy-Efficient Technologies for the Dismounted Soldier FINDINGS Based solely on an assessment of the energy efficiency characteristics of electronics currently in the Army inventory, the committee concluded that the Army's customary approach to acquiring military electronics equipment has resulted in systems that are strikingly less capable than commercial electronics with equivalent functions. Furthermore, commercial developers have learned that they can achieve other desirable military characteristics, such as reduced bulk, weight, and cost, through the active pursuit of higher energy efficiencies. The dismounted soldier, supported by the Land Warrior ensemble, will require electronics equipment with at least the same energy efficiency characteristics as commercial equipment. Army R&D must focus on translating energy efficiency into soldier effectiveness. The most critical Land Warrior subsystem, the computer/radio subsystem, is handicapped by required system interfaces to existing communications systems. Technical hurdles imposed by the Army information systems architecture will have to be overcome before the design of the computer/radio subsystem can incorporate and benefit from ASIC and system on a chip technologies. This key subsystem is locked on a trajectory that lags behind commercial energy consumption trends, and the distance between them is growing steadily. In another decade, Army systems may well be characterized by specific energy consumption 100 times higher than it would be if commercial advances were incorporated. Of the 20 significant research objectives recommended by the committee, the Army should place the most emphasis on: developing a wireless battlefield communications network developing models for optimizing energy efficiency developing advanced fueled systems keyed to the soldier system   In evaluating and determining priorities, energy efficiency must become the primary rationale for research on dismounted soldier systems. Capitalizing on experience with Land Warrior, the Army should use the following guidelines in implementing future programs: The Army must be willing to invest in new technology. The payoff in battery and other logistics (weight and bulk) savings should be considered to offset investment. Land Warrior technology should be considered separately from past investments. Research should not be constrained by the legacy of existing systems. Field and battle laboratories should be created to review and update Land Warrior operational requirements based on successful experiments with commercial equivalents.  

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Energy-Efficient Technologies for the Dismounted Soldier The vision is sound, but the science and technology insertion candidates for Land Warrior are aimed at the relatively near term. Advanced systems have not been identified that will meet the far-term power requirements.