Energy-Efficient Data Access for Pervasive Computing

能源效率对于普适计算至关重要。 小型的移动计算机，如手持设备，是由电池供电的。 他们必须小心管理有限的能源供应，以便长时间运行高要求的应用程序。 无处不在的计算机也越来越多地通过无线网络与互联网连接。然而，连接是昂贵的：通信是其功率预算的一个很大且不断增长的部分。 当前的数据访问机制加剧了这个问题-它们实质上增加了通信的能量成本，因为它们是针对性能而不是能量效率进行优化的。 第一步是建立测量基础设施，精确地捕获数据访问的通信、存储和计算成本。 下一步是描述现有分布式文件系统的能源使用情况，并确定提高能源效率的特征。 最后一步是建立一个新的，节能的文件系统，使普及的计算机保持连接，而不影响电池寿命。 因此，这项研究使普适计算设备被纳入日常活动。 例如，全天的电池寿命对于将手持计算机深入整合到课堂活动中的项目至关重要。

Energy-efficiency is vital for pervasive computing. Small, mobilecomputers such as handhelds are battery powered. They must carefullymanage their limited energy supply in order to run demandingapplications for long periods of time. Pervasive computers are alsoincreasingly well-connected to the Internet by wireless networks.However, connectivity is costly: communication is a large and growingportion of their power budgets. Current data access mechanismsexacerbate the problem---they substantially increase the energy costof communication because they are optimized for performance, notenergy-efficiency.This research investigates how to build energy-efficient distributedfile systems for pervasive computing. The first step is buildingmeasurement infrastructure that precisely captures the communication,storage, and computation costs of data access. The next step ischaracterizing the energy usage of existing distributed file systemsand identifying characteristics that increase energy-efficiency. Thefinal step is building a new, energy-efficient file system thatenables pervasive computers to maintain connectivity withoutcompromising battery lifetime. This research thus allows pervasivecomputing devices to be incorporated into everyday activities. Forexample, all-day battery life is essential for projects that deeplyintegrate handheld computers into classroom activity.