Learn More
Energy expenses are becoming an increasingly important fraction of data center operating costs. At the same time, the energy expense per unit of computation can vary significantly between two different locations. In this paper, we characterize the variation due to fluctuating electricity prices and argue that existing distributed systems should be able to(More)
There are two obvious ways to map a two-dimension relational database table onto a one-dimensional storage interface: store the table row-by-row, or store the table column-by-column. Historically, database system implementations and research have focused on the row-by row data layout, since it performs best on the most common application for database(More)
Inverse multiplexing, or network striping, allows the construction of a high-bandwidth virtual channel from a collection of multiple low-bandwidth network channels. Striping systems usually employ an immutable packet scheduling policy and allow applications to be oblivious of the way in which packets are routed to specific network channels. Though this is(More)
Tavarua is a multimedia streaming system that leverages network-striping to deliver relatively high bit rate video over present-day cellular wireless wide-area networks. The Tavarua system achieves this by building on our previously developed flexible network-striping middleware. This paper describes a motivating mobile telemedicine application, and the(More)
In North America, electricity prices exhibit both temporal and geographic variation—the later exists due to regional demand differences, transmission inefficiencies and generation diversity. Using historical market data, we characterize the variation and argue that existing distributed systems should be able to exploit it for significant economic gains. We(More)
Telemedicine has had a positive impact on some aspects of patient care. However, existing telemedicine systems that use high-quality video are inflexible, requiring investment in fixed infrastructure. We have overcome a number of technical challenges to build a mobile telemedicine system that can reliably deliver high-quality video from both stationary(More)
This paper describes an approach to building a high-quality mobile telemedicine system that overcomes the limitations of individual public wireless data networks. Public wireless data channels do not have the capacity to handle the high-bandwidth video needed for applications such as remote evaluation of trauma and stroke patients. Network striping allows(More)
  • 1