The power broker: Intelligent power management for mobile computers (original) (raw)

Controlling Energy Demand in Mobile Computing Systems

Synthesis Lectures on Mobile and Pervasive Computing, 2007

Mobile computing and pervasive computing represent major evolutionary steps in distributed systems, a line of research and development that dates back to the mid-1970s. Although many basic principles of distributed system design continue to apply, four key constraints of mobility have forced the development of specialized techniques. These include: unpredictable variation in network quality, lowered trust and robustness of mobile elements, limitations on local resources imposed by weight and size constraints, and concern for battery power consumption. Beyond mobile computing lies pervasive (or ubiquitous) computing, whose essence is the creation of environments saturated with computing and communication, yet gracefully integrated with human users. A rich collection of topics lies at the intersections of mobile and pervasive computing with many other areas of computer science.

Turducken: Hierarchical Power Management for Mobile Devices

Maintaining optimal consistency in a distributed system requires that nodes be always-on to synchronize information. Unfortunately, mobile devices such as laptops do not have adequate battery capacity for constant processing and communication. Even by powering off unnecessary components, such as the screen and disk, current laptops only have a lifetime of a few hours. Although PDAs and sensors are similarly limited in lifetime, a PDA's power requirement is an order-of-magnitude smaller than a laptop's, and a sensor's is an order-of-magnitude smaller than a PDA's. By combining these diverse platforms into a single integrated laptop, we can reduce the power cost of always-on operation. This paper presents the design, implementation, and evaluation of Turducken, a Hierarchical Power Management architecture for mobile systems. We focus on a particular instantiation of HPM, which provides high levels of consistency in a laptop by integrating two additional low power processors. We demonstrate that a Turducken system can provide battery lifetimes of up to ten times that of a standard laptop for always-on operation and three times for a system that periodically sleeps.

Power-Aware Middleware for Mobile Applications

Handbook of Energy-Aware and Green Computing, Volume 1

This chapter develops a middleware based approach to optimizing the power consumption of low-power mobile devices executing rich applications such as multimedia streaming and location based services. In mobile distributed environments, generic middleware services (e.g. caching, location management etc.) are widely used to satisfy application Quality-of-Service (QoS) needs in a cost effective manner. Such middleware services consume system resources such as storage, computation and communication and can be sources of significant power overheads when executed on low-power devices. In particular, we develop techniques for partitioning tasks to realize mobile applications into reconfigurable components; we also advocate a proxy based approach wherein components can be dynamically stopped or migrated away from a low-power device to an in-network proxy node, thereby extending the life time of the device. Specifically, 1)determine whether a reconfigurable component-based middleware framework can be utilized to achieve energy gains on low-power devices in distributed environments and 2) design and evaluate techniques for dynamically determining middleware component reconfigurations, and ascertaining the optimal frequency at which the restructuring should take place, for maximal energy and service time gains at the device. As the case study we will introduce a power-aware middleware framework (PARM) and identify some of the intrinsic requirements for the framework to be effective.

A Framework for Optimization of Power Consumption in Mobile Computing Devices

Mehran University Research Journal of Engineering and Technology, 2020

Battery driven computing devices such as laptops and cellular phones have become a necessity in this era. Mobile applications help us in daily life activities and with the rise of Internet of Things (IoT) new opportunities are open up to automate different task. However, batteries have their own limitations such as weight, cost, and size. Multiple applications and background processes running in parallel easily drain phone’s battery within 24 hours consequently annoying users by limited battery capacity. Repeated charge, recharge cycles steadily diminish the full capacity of batteries resulting in the immense decreased performance of the device. Therefore, mobile devices and mobile applications are in great need of energy-aware modules. In this paper, a survey is performed to identify the needs of the mobile user in the context of energy consumption problem. The results of survey lead authors to propose a middle layer energy aware framework to address this issue. The proposed framew...

A case study of a system-level approach to power-aware computing

ACM Transactions on Embedded Computing Systems, 2003

This paper introduces a systematic approach to power awareness in mobile, handheld computers. It describes experimental evaluations of several techniques for improving the energy efficiency of a system, ranging from the network level down to the physical level of the battery. At the network level, a new routing method based upon the power consumed by the network subsystem is shown to improve power consumption by 15% on average and to reduce latency by 75% over methods that consider only the transmitted power. At the boundary between the network and the processor levels, the paper presents the problem of local versus remote processing and derives a figure of merit for determining whether a computation should be completed locally or remotely, one that involves the relative performance of the local and remote system, the transmission bandwidth and power consumption, and the network congestion. At the processor level, the main memory bandwidth is shown to have a significant effect on the relationship between performance and CPU frequency, which in turn determines the energy savings of dynamic CPU speed-setting. The results show that accounting for the main memory bandwidth using Amdahl's law permits the performance speed-up and peak power versus the CPU frequency to be estimated to within 5%. The paper concludes with a technique for mitigating the loss of battery energy capacity with large peak currents, showing an improvement of up to 10% in battery life, albeit at some cost to the size and weight of the system.

Power Aware Computing

Series in Computer Science, 2002

Power aware computing/edited by Robert Graybill and Rami Melhem. p. cm.-(Series in computer systems) Includes bibliographical references and index.

Application-Aware Power Management

2006 IEEE International Symposium on Workload Characterization, 2006

This paper presents our approach for applicationaware power management. We combine continuous monitoring of critical workload indicators, online power and performance model usage and timely p-state control to realize application-aware power management. We present two new power management solutions enabled by our methodology: PerformanceMaximizer (PM) finds the best possible performance under specified power constraints and PowerSave (PS) saves energy while keeping performance above specified requirements. We evaluate both using the SPEC-CPU2000 suite on a Pentium M platform discussing implications of workload characteristics and benefits of being workload-aware.

Managing Shared Resources in Power Aware Systems

Mobile and portable computing devices based on microprocessors, cellular phones, portable digital agendas (PDA), etc. represent today an important part in the consumer electronic market. The commercial success of these products greatly depends on the duration of the battery support. In order to consume minimal energy during power-up, sleep, idle and underloaded conditions, many Dynamic Voltage Scaling (DVS) techniques have been proposed. In this paper, we propose a technique based on the resource reservation paradigm. The paradigm is extended to cope with shared resources and critical sections. The bandwidth reserved to each task is controlled by means of a predictor and a feedback algorithm. Taking into account the total utilization factor demand for the processor the frequency and voltage are scaled to keep the overall bandwidth close to 100%.

Constrained Power Management: Application to a multimedia mobile platform

2010 Design, Automation & Test in Europe Conference & Exhibition (DATE 2010), 2010

In this paper we provide an overview of CPM, a cross-layer framework for Constrained Power Management, and we present its application on a real use case. This framework involves different layers of a typical embedded system, ranging from device drivers to applications. The main goals of CPM are (i) to aggregate applications' QoS requirements and (ii) to exploit them to support an efficient coordination between different drivers' local optimization policies. This role is supported by a system-wide and multi-objective optimization policy which could be also changed at run-time. In this paper we mostly focus on a real use case to show the very low overhead of CPM both on the management of QoS requirements and on the tracking of hardware crossdependencies, which cannot be directly considered by local optimization policies.