RUI/CSR-PDOS: Cooperative Prefetching for Mobile Devices

许多移动计算应用程序面临的一个根本挑战是数据管理。数据应该随时随地可用。然而，对于跨一组个人设备(例如，膝上型计算机、PDA和移动电话)管理用户的个人数据(例如，数据文件、电子邮件和高速缓存的网页)而言，该任务尤其难以支持。移动环境的两个特性使数据管理特别具有挑战性：网络断开和设备资源限制，特别是能源限制。这项工作的目标是为收集个人设备提供最大的个人数据可用性和一致性以及最大的聚合设备寿命。为了实现这一目标，该项目开发了一套协作预取算法，使设备能够在连接到信息源时检索相关数据。此外，算法有效地在设备集合上分配执行预取的能量负担。评估调查了在笔记本电脑和iPAQ集合上运行的实现中的算法的性能。考虑了两个主要指标：设备的总寿命和用户请求数据的命中率。这项工作的主要影响将是提高移动设备和应用程序的可用性，并最大化移动设备的寿命。此外，参与该项目的学生是来自芒特霍利奥克学院的本科生，该学院是美国最好的全女性本科生机构之一。因此，该项目还将有助于提高妇女在系统研究中的总体参与度。

A fundamental challenge for many mobile computing applications is datamanagement. Data should be available anywhere at anytime. However,this task is particularly difficult to support with respect tomanaging a user's personal data (e.g., data files, email, and cachedweb pages) across a collection of personal devices (e.g., a laptop,PDA, and mobile phone). Two properties of the mobile environment makedata management particularly challenging: network disconnection anddevice resource constraints, particularly energy constraints. Thegoal of this work is to provide maximal availability and consistencyof personal data as well as maximal aggregate device lifetime for acollection of personal devices. To accomplish this goal, the projectdevelops a set of cooperative prefetching algorithms that enabledevices to retrieve relevant data when connected to the informationsource. Further, the algorithms efficiently distribute the energyburden of performing prefetching across the collection of devices.The evaluation investigates the performance of the algorithms in animplementation running on a collection of laptop computers and iPAQs.Two primary metrics are considered: the aggregate lifetime of thedevices and the hit rate of user requests for data. The overarchingimpacts of this work will be improved usability of mobile devices andapplications and maximization of mobile device lifetime. Further, thestudent participants in this project are undergraduate women fromMount Holyoke College, one of the nation's finest all-womenundergraduate institutions. Therefore, the project will also serve toimprove the overall participation of women in systems research.