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563
System architecture directions for networked sensors
- IN ARCHITECTURAL SUPPORT FOR PROGRAMMING LANGUAGES AND OPERATING SYSTEMS
, 2000
"... Technological progress in integrated, low-power, CMOS communication devices and sensors makes a rich design space of networked sensors viable. They can be deeply embedded in the physical world or spread throughout our environment. The missing elements are an overall system architecture and a methodo ..."
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Cited by 1789 (58 self)
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Technological progress in integrated, low-power, CMOS communication devices and sensors makes a rich design space of networked sensors viable. They can be deeply embedded in the physical world or spread throughout our environment. The missing elements are an overall system architecture and a methodology for systematic advance. To this end, we identify key requirements, develop a small device that is representative of the class, design a tiny event-driven operating system, and show that it provides support for efficient modularity and concurrency-intensive operation. Our operating system fits in 178 bytes of memory, propagates events in the time it takes to copy 1.25 bytes of memory, context switches in the time it takes to copy 6 bytes of memory and supports two level scheduling. The analysis lays a groundwork for future architectural advances.
Pervasive Computing: Vision and Challenges
- IEEE Personal Communications
, 2001
"... This paper discusses the challenges in computer systems research posed by the emerging field of pervasive computing. It first examines the relationship of this new field to its predecessors: distributed systems and mobile computing. It then identifies four new research thrusts: effective use of smar ..."
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Cited by 686 (22 self)
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This paper discusses the challenges in computer systems research posed by the emerging field of pervasive computing. It first examines the relationship of this new field to its predecessors: distributed systems and mobile computing. It then identifies four new research thrusts: effective use of smart spaces, invisibility, localized scalability, and masking uneven conditioning. Next, it sketches a couple of hypothetical pervasive computing scenarios, and uses them to identify key capabilities missing from today's systems. The paper closes with a discussion of the research necessary to develop these capabilities.
A scheduling model for reduced CPU energy
- ANNUAL SYMPOSIUM ON FOUNDATIONS OF COMPUTER SCIENCE
, 1995
"... The energy usage of computer systems is becoming an important consideration, especially for batteryoperated systems. Various methods for reducing energy consumption have been investigated, both at the circuit level and at the operating systems level. In this paper, we propose a simple model of job s ..."
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Cited by 558 (3 self)
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The energy usage of computer systems is becoming an important consideration, especially for batteryoperated systems. Various methods for reducing energy consumption have been investigated, both at the circuit level and at the operating systems level. In this paper, we propose a simple model of job scheduling aimed at capturing some key aspects of energy minimization. In this model, each job is to be executed between its arrival time and deadline by a single processor with variable speed, under the assumption that energy usage per unit time, P, is a convex function of the processor speed s. We give an off-line algorithm that computes, for any set of jobs, a minimum-energy schedule. We then consider some on-line algorithms and their competitive performance for the power function P(s) = sp where p 3 2. It is shown that one natural heuristic, called the Average Rate heuristic, uses at most a constant times the minimum energy required. The analysis involves bounding the largest eigenvalue in matrices of a special type.
Real-Time Dynamic Voltage Scaling for Low-Power Embedded Operating Systems
, 2001
"... In recent years, there has been a rapid and wide spread of nontraditional computing platforms, especially mobile and portable computing devices. As applications become increasingly sophisticated and processing power increases, the most serious limitation on these devices is the available battery lif ..."
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Cited by 501 (4 self)
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In recent years, there has been a rapid and wide spread of nontraditional computing platforms, especially mobile and portable computing devices. As applications become increasingly sophisticated and processing power increases, the most serious limitation on these devices is the available battery life. Dynamic Voltage Scaling (DVS) has been a key technique in exploiting the hardware characteristics of processors to reduce energy dissipation by lowering the supply voltage and operating frequency. The DVS algorithms are shown to be able to make dramatic energy savings while providing the necessary peak computation power in general-purpose systems. However, for a large class of applications in embedded real-time systems like cellular phones and camcorders, the variable operating frequency interferes with their deadline guarantee mechanisms, and DVS in this context, despite its growing importance, is largely overlooked/under-developed. To provide real-time guarantees, DVS must consider deadlines and periodicity of real-time tasks, requiring integration with the real-time scheduler. In this paper, we present a class of novel algorithms called real-time DVS (RT-DVS) that modify the OS's real-time scheduler and task management service to provide significant energy savings while maintaining real-time deadline guarantees. We show through simulations and a working prototype implementation that these RT-DVS algorithms closely approach the theoretical lower bound on energy consumption, and can easily reduce energy consumption 20% to 40% in an embedded real-time system.
Energy-aware adaptation for mobile applications
- 17TH ACM SYMPOSIUM ON OPERATING SYSTEMS PRINCIPLES (SO SP '99), PUBLISHED AS OPERATING SYSTEMS REVIEW
, 1999
"... In this paper, we demonstrate that a collaborative relationship between the operating system and applications can be used to meet user-specified goals for battery duration. We first show how applications can dynamically modify their behavior to conserve energy. We then show how the Linux operating s ..."
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Cited by 334 (19 self)
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In this paper, we demonstrate that a collaborative relationship between the operating system and applications can be used to meet user-specified goals for battery duration. We first show how applications can dynamically modify their behavior to conserve energy. We then show how the Linux operating system can guide such adaptation to yield a batterylife of desired duration. By monitoring energy supply and demand, it is able to select the correct tradeoff between energy conservation and application quality. Our evaluation shows that this approach can meet goals that extend battery life by as much as 30%.
Mobile ad hoc networking: imperatives and challenges
, 2003
"... Mobile ad hoc networks (MANETs) represent complex distributed systems that comprise wireless mobile nodes that can freely and dynamically self-organize into arbitrary and temporary, "ad-hoc" network topologies, allowing people and devices to seamlessly internetwork in areas with no pre-exi ..."
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Cited by 317 (8 self)
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Mobile ad hoc networks (MANETs) represent complex distributed systems that comprise wireless mobile nodes that can freely and dynamically self-organize into arbitrary and temporary, "ad-hoc" network topologies, allowing people and devices to seamlessly internetwork in areas with no pre-existing communication infrastructure, e.g., disaster recovery environments. Ad hoc networking concept is not a new one, having been around in various forms for over 20 years. Traditionally, tactical networks have been the only communication networking application that followed the ad hoc paradigm. Recently, the introduction of new technologies such as the Bluetooth, IEEE 802.11 and Hyperlan are helping enable eventual commercial MANET deployments outside the military domain. These recent evolutions have been generating a renewed and growing interest in the research and development of MANET. This paper attempts to provide a comprehensive overview of this dynamic field. It first explains the important role that mobile ad hoc networks play in the evolution of future wireless technologies. Then, it reviews the latest research activities in these areas, including a summary of MANET's characteristics, capabilities, applications, and design constraints. The paper concludes by presenting a set of challenges and problems requiring further research in the future.
The Simulation and Evaluation of Dynamic Voltage Scaling Algorithms
, 1998
"... The reduction of energy consumption in microprocessors can be accomplished without impacting the peak performance through the use of dynamic voltage scaling (DVS). This approach varies the processor voltage under software control to meet dynamically varying performance requirements. This paper prese ..."
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Cited by 303 (5 self)
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The reduction of energy consumption in microprocessors can be accomplished without impacting the peak performance through the use of dynamic voltage scaling (DVS). This approach varies the processor voltage under software control to meet dynamically varying performance requirements. This paper presents a foundation for the simulation and analysis of DVS algorithms. These algorithms are applied to a benchmark suite specifically targeted for PDA devices. 2.
Comparing Algorithms for Dynamic Speed-Setting of a Low-Power CPU
, 1995
"... To take advantage of the full potential of ubiquitous computing, we will need systems which minimize powerconsumption. Weiser et al. and others have suggested that this may be accomplished by a CPU which dynamically changes speed and voltage, thereby saving energy by spreading run cycles into idle t ..."
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Cited by 301 (0 self)
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To take advantage of the full potential of ubiquitous computing, we will need systems which minimize powerconsumption. Weiser et al. and others have suggested that this may be accomplished by a CPU which dynamically changes speed and voltage, thereby saving energy by spreading run cycles into idle time. Here we continue this research, using a simulation to compare a number of policies for dynamic speed-setting. Our work clarifies a fundamental power vs. delay tradeoff, as well as the role of prediction and of smoothing in dynamic speed-setting policies. We conclude that success seemingly depends more on simple smoothing algorithms than on sophisticated prediction techniques, but defer to the replication of these results on future variable-speed systems. 1 Introduction Recent developments in ubiquitous computing make it likely that the future will see a proliferation of cordless computing devices. Clearly it will be advantageous for such devices to minimize power-consumption. The top p...
A survey of energy efficient network protocols for wireless networks
- Wireless Networks
, 2001
"... Abstract. Wireless networking has witnessed an explosion of interest from consumers in recent years for its applications in mobile and personal communications. As wireless networks become an integral component of the modern communication infrastructure, energy efficiency will be an important design ..."
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Cited by 278 (1 self)
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Abstract. Wireless networking has witnessed an explosion of interest from consumers in recent years for its applications in mobile and personal communications. As wireless networks become an integral component of the modern communication infrastructure, energy efficiency will be an important design consideration due to the limited battery life of mobile terminals. Power conservation techniques are commonly used in the hardware design of such systems. Since the network interface is a significant consumer of power, considerable research has been devoted to low-power design of the entire network protocol stack of wireless networks in an effort to enhance energy efficiency. This paper presents a comprehensive summary of recent work addressing energy efficient and low-power design within all layers of the wireless network protocol stack.
Drowsy Caches: Simple Techniques for Reducing Leakage Power
- PROC. 29TH INT’L SYMP. COMPUTER ARCHITECTURE
, 2002
"... On-chip caches represent a sizable fraction of the total power consumption of microprocessors. Although large caches can significantly improve performance, they have the potential to increase power consumption. As feature sizes shrink, the dominant component of this power loss will be leakage. Howev ..."
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Cited by 251 (1 self)
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On-chip caches represent a sizable fraction of the total power consumption of microprocessors. Although large caches can significantly improve performance, they have the potential to increase power consumption. As feature sizes shrink, the dominant component of this power loss will be leakage. However, during a fixed period of time the activity in a cache is only centered on a small subset of the lines. This behavior can be exploited to cut the leakage power of large caches by putting the cold cache lines into a state preserving, low-power drowsy mode. Moving lines into and out of drowsy state incurs a slight performance loss. In this paper we investigate policies and circuit techniques for implementing drowsy caches. We show that with simple architectural techniques, about 80%-90 % of the cache lines can be maintained in a drowsy state without affecting performance by more than 1%. According to our projections, in a 0.07um CMOS process, drowsy caches will be able to reduce the total energy (static and dynamic) consumed in the caches by 50%-75%. We also argue that the use of drowsy caches can simplify the design and control of low-leakage caches, and avoid the need to completely turn off selected cache lines and lose their state.
