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226
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 670 (20 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.
Agile Application-Aware Adaptation for Mobility
- SOSP-16
, 1997
"... In this paper we show that application-aware adaptation, a collaborative partnership between the operating system and applications, offers the most general and effective approach to mobile information access. We describe the design of Odyssey, a prototype implementing this approach, and show how it ..."
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Cited by 503 (31 self)
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In this paper we show that application-aware adaptation, a collaborative partnership between the operating system and applications, offers the most general and effective approach to mobile information access. We describe the design of Odyssey, a prototype implementing this approach, and show how it supports concurrent execution of diverse mobile applications. We identify agility as a key attribute of adaptive systems, and describe how to quantify and measure it. We present the results of our evaluation of Odyssey, indicating performance improvements up to a factor of 5 on a benchmark of three applications concurrently using remote services over a network with highly variable bandwidth.
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 324 (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%.
Performance Guarantees for Web Server End-Systems: A Control-Theoretical Approach
- IEEE Transactions on Parallel and Distributed Systems
, 2001
"... The Internet is undergoing substantial changes from a communication and browsing infrastructure to a medium for conducting business and marketing a myriad of services. The World Wide Web provides a uniform and widely-accepted application interface used by these services to reach multitudes of client ..."
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Cited by 268 (19 self)
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The Internet is undergoing substantial changes from a communication and browsing infrastructure to a medium for conducting business and marketing a myriad of services. The World Wide Web provides a uniform and widely-accepted application interface used by these services to reach multitudes of clients. These changes place the web server at the center of a gradually emerging eservice infrastructure with increasing requirements for service quality and reliability guarantees in an unpredictable and highly-dynamic environment.
The Ninja architecture for robust Internet-scale systems and services
- Computer Networks
, 2001
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Nettimer: A Tool for Measuring Bottleneck Link Bandwidth
- In Proceedings of the USENIX Symposium on Internet Technologies and Systems
, 2001
"... Measuring the bottleneck link bandwidth along a path is important for understanding the performance of many Internet applications. Existing tools to measure bottleneck bandwidth are relatively slow, can only measure bandwidth in one direction, and/or actively send probe packets. We present the netti ..."
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Cited by 203 (1 self)
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Measuring the bottleneck link bandwidth along a path is important for understanding the performance of many Internet applications. Existing tools to measure bottleneck bandwidth are relatively slow, can only measure bandwidth in one direction, and/or actively send probe packets. We present the nettimer bottleneck link bandwidth measurement tool, the libdpcap distributed packet capture library, and experiments quantifying their utility. We test nettimer across a variety of bottleneck network technologies ranging from 19.2Kb/s to 100Mb/s, wired and wireless, symmetric and asymmetric bandwidth, across local area and crosscountry paths, while using both one and two packet capture hosts. In most cases, nettimer has an error of less than 10%, but at worst has an error of 40%, even on cross-country paths of 17 or more hops. It converges within 10KB of the first large packet arrival while consuming less than 7% of the network traffic being measured.
Adapting Multimedia Internet Content for Universal Access
- IEEE Transactions on Multimedia
, 1999
"... Content delivery over the Internet needs to address both the multimedia nature of the content and the capabilities of the diverse client platforms the content is being delivered to. We present a system that adapts multimedia Web documents to optimally match the capabilities of the client device requ ..."
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Cited by 195 (2 self)
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Content delivery over the Internet needs to address both the multimedia nature of the content and the capabilities of the diverse client platforms the content is being delivered to. We present a system that adapts multimedia Web documents to optimally match the capabilities of the client device requesting it. This system has two key components: (1) A representation scheme called the InfoPyramid that provides a multi-modal, multi-resolution representation hierarchy for multimedia. (2) A customizer that selects the best content representation to meet the client capabilities while delivering the most value. We model the selection process as a resource allocation problem in a generalized rate-distortion framework. In this framework, we address the issue of both multiple media types in a Web document and multiple resource types at the client. We extend this framework to allow prioritization on the content items in a Web document. We illustrate our content adaptation technique with a web ...
Mobile computing with the rover toolkit
- IEEE Transactions on Computers
, 1997
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Software Strategies for Portable Computer Energy Management
, 1998
"... Limiting the energy consumption of computers, especially portables, is becoming increasingly important. Thus, new energy-saving computer components and architectures have been and continue to be developed. Many architectural features have both high-performance and low-power modes, with the mode se ..."
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Cited by 153 (1 self)
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Limiting the energy consumption of computers, especially portables, is becoming increasingly important. Thus, new energy-saving computer components and architectures have been and continue to be developed. Many architectural features have both high-performance and low-power modes, with the mode selection under software control. The problem is to minimize energy consumption while not significantly impacting the effective performance. We group the software control issues as follows: transition, load-change, and adaptation. The transition problem is deciding when to switch to low-power, reduced-functionality modes. The load-change problem is determining how to modify the load on a component so that it can make further use of its low-power modes. The adaptation problem is determining how to create software that allows components to be used in novel, power-saving ways. We survey implemented and proposed solutions to software energy management issues created by existing and suggested hardware innovations.
WebOS: Operating System Services for Wide Area Applications
"... In this paper, we demonstrate the power of providing a common set of Operating System services to wide-area applications, including mechanisms for naming, persistent storage, remote process execution, resource management, authentication, and security. On a single machine, application developers can ..."
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Cited by 128 (17 self)
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In this paper, we demonstrate the power of providing a common set of Operating System services to wide-area applications, including mechanisms for naming, persistent storage, remote process execution, resource management, authentication, and security. On a single machine, application developers can rely on the local operating system to provide these abstractions. In the wide area, however, application developers are forced to build these abstractions themselves or to do without. This ad-hoc approach often results in individual programmers implementing non-optimal solutions, wasting both programmer effort and system resources. To address these problems, we are building a system, WebOS, that provides basic operating systems services needed to build applications that are geographically distributed, highly available, incrementally scalable, and dynamically reconfigurable. Experience with a number of applications developed under WebOS indicates that it simplifies system development and improves resource utilization. In particular, we use WebOS to implement Rent-A-Server to provide dynamic replication of overloaded Web services across the wide area in response to client demands.
