Energy-efficient network memory for ubiquitous devices

Mobile Computing, IEEE …, 2006

Virtual memory is considered to be an unlimited resource in desktop or notebook computers with high storage capabilities. However, in wireless mobile devices, like palmtops and personal digital assistants (PDAs), storage memory is limited or absent due to weight, size, and power constraints, so that swapping over remote memory devices can be considered as a viable alternative. However, power-hungry wireless network interface cards (WNICs) may limit the battery lifetime and application performance if not efficiently exploited. In this paper, we study performance and energy of network swapping in comparison with swapping on local microdrives and flash memories. We report the results of extensive experiments conducted on different WNICs and local swapping devices, using both synthetic and natural benchmarks. Our study points out that remote swapping over power-manageable WNICs can be more efficient than local swapping, especially in bursty workload conditions. Such conditions can be forced where possible by reshaping swapping requests to increase energy efficiency and performance.

Tehnicki vjesnik - Technical Gazette, 2019

This paper discusses research results with regard to energy-efficient transmission of serialised data between servers and mobile devices. A test environment was created in which the research authors primarily measured electricity consumption during communication between a mobile device and server. Numerical results were used to determine how well data serialisation was performed on a dedicated server and its effects on the power consumption of a mobile device. The time spent in data serialisation and the size of the serialised file were found to significantly influence energy consumption. Based on that fact, results have been used to create a mathematical model which was later introduced with functional forms. The main variables in those functional forms were time of serialisation and size of a serialised file. The data collected through this research has been used for an experimental API-CB Saver, which based on mathematical models chooses the most favourable manner of serialisation and compression in real time. The results collected during the tests show that the CBSaver-Api approach performs with greater energy efficiency than current techniques. Furthermore, with optimal selection of data serialisation type and compression level in real time the considered system shows better performance in power saving. According to the results, the API-CBSaver tests indicate the direction which one should take for the purposes of improving energy efficiency.

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

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.

2002

Abstract Pervasive computing devices such as Personal Digital Assistants (PDAs) and laptop computers are becoming increasingly ubiquitous. The future promises even more advanced devices such as digital watches, jewelry, and even clothing. However, as pervasive devices become more widely used for more advanced applications, their resource limitations are becoming more apparent. In this work, we focus on data management and power limitations.

2003

This paper is motivated by a simple question: what are the energy consumption characteristics of mobile storage alternatives? To answer this question, we are faced with a design space of multiple dimensions. Two important dimensions are the type of storage technologies and the type of file systems. In this paper, we explore some options along each of these two dimensions. We have constructed a logical-disk system, which can be configured to run on different storage technologies and to emulate the behavior of different file systems. As we explore these configuration options, we find that the energy behavior is determined by a complex interaction of three factors: the power management mechanism of the storage device, the distribution of idleness in the workload, and the file system strategies that attempt to exploit and bridge these first two factors.

NEM summit, …, 2009

Corresponding author: Farhan Azmat Ali, IBBT-IBCN, Deparment of Information Technology, Ghent University, Gaston Crommenlaan 8 bus 201, 9050 Gent, +32 9 3314900, farhan.azmatali@intec.ugent.be ... F. Azmat Ali 1 , P. Simoens 1 , B. Vankeirsbilck 1 , L. ...

Proceedings of the 2nd ACM …, 2004

Wireless networked embedded terminals like personal digital assistants, cell-phones or sensor nodes are typically memory constrained devices. This limitation prevents the development of applications that require a large amount of run-time memory space. In a wired cum wireless scenario, a potentially unlimited amount of virtual memory can be found on remote servers installed on the wired network. However, virtual memory access requires performance constrained and lossless data flows against terminal handover between coverage areas. In this work, we present an infrastructure aimed at providing efficient remote memory access to mobile terminals in a wireless LAN connected to a multi-hop network. The behavior of the infrastructure has been theoretically studied, implemented and tested w.r.t. various traffic conditions and handover events.

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.

2012

With the widespread development of cloud computing and high speed communications, end users store or retrieve video, music, photo and other contents over the cloud or the local network for video-on-demand, wireless display and other usages. The traditional I/O model in a mobile platform consumes time and resources due to excessive memory access and copying when transferring content from a source device, e.g., network controller, to a destination device, e.g., hard disk. This model introduces unnecessary overhead and latency, negatively impacting the performance and energy consumption of content-intensive uses. In this paper, we introduce DirectPath, a low overhead I/O architecture that optimizes content movement within a platform to improve energy efficiency and throughput performance. We design, implement and validate the Direct-Path architecture for a network-to-storage file download usage model. We evaluate and quantify DirectPath's energy and performance benefits on both laptop and small formfactor SoC based platforms. The measurement results show that DirectPath reduces energy consumption by up to 50 % and improves throughput performance by up to 137 %.