Power-Aware Network Swapping for Wireless Palmtop PCS

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.

2004

To reduce energy consumption (EC), a mobile handset system can be designed in such a way that while the data-receiving unit in a mobile handset is receiving and monitoring data packets, the rest part of the handset (i.e., a processing unit and a user interface) is switched off into a sleep mode. In this paper, we study the timing when the rest part of the handset should wake up. Several schemes (i.e., Always-ON, Always-OFF, Wake-up upon Arrival, Wake-up upon Full, and the fractional threshold scheme) are studied and compared in terms of energy saving and the packet dropping probability (PDP). We formulate the total EC for all theses schemes analytically. Furthermore, we show how to choose optimal thresholds for the fractional threshold scheme for the following two-optimization problems: 1) minimizing the switch-on rate with a bound on the PDP and 2) minimizing the total EC with a bound on the PDP. Our study shows that the fractional threshold scheme is the best scheme. Simulations are carried out to validate analytic models. Index Terms-Energy consumption, mobile handset, sleep mode, wake-up mechanism. I. INTRODUCTION O NE of the critical limiting operational factors for mobile handsets is that their operation time is restricted by the battery capacity, even in stand-alone mode [2]. Therefore, designing the system in an energy consumption (EC)-aware manner is imperative [3], [4], and it is one of the primary objectives in the design of mobile handsets [5]. Significant reduction of battery size and weight can be difficult so that alternative strategies need to be employed toward the goal of energy savings in both communication and networking aspects [5], [6]. Operations of mobile handsets may significantly consume battery energy. The components consuming energy in a mobile handset can be designed in such a way that while the data-receiving unit (DRU), a fixed-size memory queue in the handset for buffering data packets, is receiving and monitoring data packets, the rest part of the handset, a user interface and a processing unit (PU) that processes received data packets, is

Elektronika Ir Elektrotechnika, 2009

2003

In this report we present a new power management infrastructure developed for the Linux operating system release running on the HP's SmartBadge4 wearable computer. Based on this infrastructure, we implemented a new methodology for optimizing the energy consumption of wireless portable devices. The server knowledge of the workload is exploited to efficiently drive the wireless interface of the client during data transfer over the wireless channel. We tested our methodology on HP's SmartBadgeIV wearable device running a HP's MPEG4 streaming video application. Using our technique we measured energy savings of more than 67% when no power management is used on the WLAN interface. In addition, we save as much as 50% of energy with respect to using power management implemented as a part of the 802.11b standard. All of the energy savings are obtained with no performance loss on the video playback.

Energy Procedia, 2004

A detailed power analysis of a multi-radio mobile platform highlights the complex tradeoffs between the computation, storage, and communication subsystems. The particular mobile device, which does not include an LCD or other on-board display, can be used as a source for audio or video media files or a source/sink for secure data transfers. A version of the device has been augmented with fine-grained power monitoring capability and used to obtain detailed measurements of power dissipation in the various subsystems. Analysis of these measurements sheds light on the power consumption characteristics of different applications, thereby providing hints to system designers about potential areas for optimization. Specifically, this work contrasts the power efficiency of the various wireless technologies supported by the system.

ACM SIGMETRICS Performance Evaluation …, 2008

Wireless Network Interface Cards (WNICs) are part of every portable device, where efficient energy management plays a significant role in extending the device's battery life. The goal of efficient energy management is to match the performance of the WNIC to the network activity shaped by a running application. In the case of interactive applications on mobile systems, network I/O is largely driven by user interactions. Current solutions either require application modifications or lack a sufficient context of execution that is crucial in making accurate and timely predictions. This paper proposes a range of user-interaction-aware mechanisms that utilize a novel approach of monitoring a user's interaction with applications through the capture and classification of mouse events. This approach yields considerable improvements in energy savings and delay reductions of the WNIC, while significantly improving the accuracy, timeliness, and computational overhead of predictions when compared to existing state-of-the-art solutions.

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...

2006

The popularity of mobile devices is growing rapidly. Due to the increase in application complexity, and the limited power supply in most mobile systems, energy optimization has become a popular research area. Different approaches have been used is lowering the energy cost. These include a variety of hardware and software techniques. In this research, we propose a novel technique that uses the Smart Caching approach cooperating with the Direct memory Access and the page caching mechanisms to keep process memory footprints small. More memory nodes thus can be put into a power-saving mode. As a result, the battery-powered supply of a mobile device can last longer. Experiments were conducted on a simulated operating system modified towards different energysaving techniques. Analysis and comparisons were made to demonstrate the effectiveness of our approach.

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.

2011 International Green Computing Conference and Workshops, 2011

Recent development of sophisticated smartphones has made them indispensable part of our everyday life. However, advances in battery technology cannot keep up with the demand for longer battery life. Subsequently, energy efficiency has become one of the most important factors in designing smartphones. Multitasking and better multimedia features in the mobile applications continuously push memory requirements further, making energy optimizations for memory critical. Mobile RAM is already optimized for energy efficiency at the hardware level. It also provides power state switching interfaces to the operating system which enables the OS level energy optimizations. Many RAM optimizations have been explored for computer systems and in this paper we explore their applicability to smartphone hardware. In addition, we apply those optimizations to the newly emerging Phase Change Memory and study their energy efficiency and performance. Finally, we propose a hybrid approach to take the advantage of both Mobile RAM and Phase Change Memory. Results show that our hybrid mechanism can save more than 98% of memory energy as compared to the standard smartphone system with negligible impact on user experience.