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558
Energy-Aware Wireless Microsensor Networks
- IEEE Signal Processing Magazine
, 2002
"... This article describes architectural and algorithmic approaches that designers can use to enhance the energy awareness of wireless sensor networks. The article starts off with an analysis of the power consumption characteristics of typical sensor node architectures and identifies the various factors ..."
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Cited by 302 (1 self)
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This article describes architectural and algorithmic approaches that designers can use to enhance the energy awareness of wireless sensor networks. The article starts off with an analysis of the power consumption characteristics of typical sensor node architectures and identifies the various factors that affect system lifetime. We then present a suite of techniques that perform aggressive energy optimization while targeting all stages of sensor network design, from individual nodes to the entire network. Maximizing network lifetime requires the use of a well-structured design methodology, which enables energy -aware design and operation of all aspects of the sensor network, from the underlying hardware platform to the application software and network protocols. Adopting such a holistic approach ensures that energy awareness is incorporated not only into individual sensor nodes but also into groups of communicating nodes and the entire sensor network. By following an energy-aware design methodology based on techniques such as in this article, designers can enhance network lifetime by orders of magnitude.
ECOSystem: Managing Energy as a First Class Operating System Resource
, 2002
"... Energy consumption has recently been widely recognized as a major challenge of computer systems design. This paper explores how to support energy as a first-class operating system resource. Energy, because of its global system nature, presents challenges beyond those of conventional resource managem ..."
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Cited by 221 (5 self)
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Energy consumption has recently been widely recognized as a major challenge of computer systems design. This paper explores how to support energy as a first-class operating system resource. Energy, because of its global system nature, presents challenges beyond those of conventional resource management. To meet these challenges we propose the Currentcy Model that unifies energy accounting over diverse hardware components and enables fair allocation of available energy among applications. Our particular goal is to extend battery lifetime by limiting the average discharge rate and to share this limited resource among competing tasks according to user preferences. To demonstrate how our framework supports explicit control over the battery resource we implemented ECOSystem, a modified Linux, that incorporates our currentcy model. Experimental results show that ECOSystem accurately accounts for the energy consumed by asynchronous device operation, can achieve a target battery lifetime, and proportionally shares the limited energy resource among competing tasks.
Dynamic and Aggressive Scheduling Techniques for Power-Aware Real-Time Systems
, 2001
"... In this paper, we address power-aware scheduling of periodic hard real-time tasks using dynamic voltage scaling. Our solution includes three parts: (a) a static (off-line) solution to compute the optimal speed, assuming worst-case workload for each arrival, (b) an on-line speed reduction mechanism t ..."
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Cited by 204 (24 self)
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In this paper, we address power-aware scheduling of periodic hard real-time tasks using dynamic voltage scaling. Our solution includes three parts: (a) a static (off-line) solution to compute the optimal speed, assuming worst-case workload for each arrival, (b) an on-line speed reduction mechanism to reclaim energy by adapting to the actual workload, and (c) an online, adaptive and speculative speed adjustment mechanism to anticipate early completions of future executions by using the average-case workload information. All these solutions still guarantee that all deadlines are met. Our simulation results show that the reclaiming algorithm saves a striking 50% of the energy over the static algorithm. Further, our speculative techniques allow for an additional approximately 20% savings over the reclaiming algorithm. In this study, we also establish that solving an instance of the static power-aware scheduling problem is equivalent to solving an instance of the rewardbased scheduling problem [1, 4] with concave reward functions. 1
Power Conscious Fixed Priority Scheduling for Hard Real-Time Systems
, 1999
"... Power efficient design of real-time systems based on programmable processors becomes more important as system functionality is increasingly realized through software. This paper presents a powerefficient version of a widely used fixed priority scheduling method. The method yields a power reduction b ..."
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Cited by 200 (5 self)
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Power efficient design of real-time systems based on programmable processors becomes more important as system functionality is increasingly realized through software. This paper presents a powerefficient version of a widely used fixed priority scheduling method. The method yields a power reduction by exploiting slack times, both those inherent in the system schedule and those arising from variations of execution times. The proposed run-time mechanism is simple enough to be implemented in most kernels. Experimental results show that the proposed scheduling method obtains a significant power reduction across several kinds of applications.
Improving Dynamic Voltage Scaling Algorithms with PACE
, 2001
"... This paper addresses algorithms for dynamically varying (scaling) CPU speed and voltage in order to save energy. Such scaling is useful and effective when it is immaterial when a task completes, as long as it meets some deadline. We show how to modify any scaling algorithm to keep performance the sa ..."
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Cited by 174 (2 self)
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This paper addresses algorithms for dynamically varying (scaling) CPU speed and voltage in order to save energy. Such scaling is useful and effective when it is immaterial when a task completes, as long as it meets some deadline. We show how to modify any scaling algorithm to keep performance the same but minimize expected energy consumption. We refer to our approach as PACE (Processor Acceleration to Conserve Energy) since the resulting schedule increases speed as the task progresses. Since PACE depends on the probability distribution of the task's work requirement, we present methods for estimating this distribution and evaluate these methods on a variety of real workloads. We also show how to approximate the optimal schedule with one that changes speed a limited number of times. Using PACE causes very little additional overhead, and yields substantial reductions in CPU energy consumption. Simulations using real workloads show it reduces the CPU energy consumption of previously published algorithms by up to 49.5%, with an average of 20.6%, without any effect on performance.
Speed scaling to manage energy and temperature
- Journal of the ACM
"... We first consider online speed scaling algorithms to min-imize the energy used subject to the constraint that every job finishes by its deadline. We assume that the power re-quired to run at speed s is P s s. We provide a tight bound on the competitive ratio of the previously pro-posed Optimal A ..."
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Cited by 167 (16 self)
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We first consider online speed scaling algorithms to min-imize the energy used subject to the constraint that every job finishes by its deadline. We assume that the power re-quired to run at speed s is P s s. We provide a tight bound on the competitive ratio of the previously pro-posed Optimal Available algorithm. This improves the best known competitive ratio by a factor of . We then intro-duce a new online algorithm, and show that this algorithm’s competitive ratio is at most e. This competi-tive ratio is significantly better and is approximately e for large . Our result is essentially tight for large . In particular, as approaches infinity, we show that any al-gorithm must have competitive ratio e (up to lower order terms). We then turn to the problem of dynamic speed scaling to minimize the maximum temperature that the device ever reaches, again subject to the constraint that all jobs finish by their deadlines. We assume that the device cools accord-ing to Fourier’s law. We show how to solve this problem in polynomial time, within any error bound, using the Ellip-soid algorithm. 1.
Synthesis Techniques for Low-power Hard Real-time
- Systems on Variable Voltage Processors,” in IEEE Real-time Systems Symposium,
, 1998
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Power optimization of real-time embedded systems on variable speed processors
, 2000
"... Power eficient design of real-time embedded systems based on programmable processors becomes more important as system functionality is increasingly realized through software. This pa-perpresents a power optimization method for real-time embedded applications on a variable speed processor: The method ..."
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Cited by 129 (0 self)
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Power eficient design of real-time embedded systems based on programmable processors becomes more important as system functionality is increasingly realized through software. This pa-perpresents a power optimization method for real-time embedded applications on a variable speed processor: The method com-bines off-line and on-line components. The off-line component determines the lowest possible maximum processor speed while guaranteeing deadlines of all tasks. The on-line component dy-namically varies the processor speed or bring a processor into a power-down mode according to the status of task set in order to exploit execution time variations and idle intervals. Experimen-tal results show that the proposed method obtains a signijicant power reduction across several kinds of applications. 1
Algorithms for power savings
- In SODA ’03: Proceedings of the fourteenth annual ACM-SIAM symposium on Discrete algorithms
, 2003
"... This paper examines two di erent mechanisms for saving power in battery-operated embedded systems. The rst is that the system can be placed in a sleep state if it is idle. However, a xed amount of energy is required to bring the system back into an active state in which it can resume work. The secon ..."
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Cited by 129 (6 self)
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This paper examines two di erent mechanisms for saving power in battery-operated embedded systems. The rst is that the system can be placed in a sleep state if it is idle. However, a xed amount of energy is required to bring the system back into an active state in which it can resume work. The second way inwhichpower savings can be achieved is by varying the speed at which jobs are run. We utilize a power consumption curve P (s) whichindicates the power consumption level given a particular speed. We assume that P (s) isconvex, non-decreasing and non-negative for s 0. The problem is to schedule arriving jobs in a way that minimizes total energy use and so that each job is completed after its release time and before its deadline. We assume that all jobs can be preempted and resumed at no cost. Although each problem has been considered separately, this is the rst theoretical analysis of systems that can use both mechanisms. We givean o ine algorithm that is within a factor of two of the optimal algorithm. We alsogivean online algorithm with a constant competitive ratio. 1
Power-aware scheduling for periodic real-time tasks. to appear in
- IEEE Trans. on Computers
, 2003
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