Low Power system Design techniques for mobile computers

Portable products are being used increasingly. Because these systems are battery powered, reducing power consumption is vital. In this report we give the properties of low power design and techniques to exploit them on the architecture of the system. We focus on: min imizing capacitance, avoiding unnecessary and wasteful activity, and reducing voltage and frequency. We review energy reduction techniques in the architecture and design of a hand-held computer and the wireless communication system, including error control, sys tem decomposition, communication and MAC protocols, and low power short range net works

Design techniques for low-power systems

Portable products are being used increasingly. Because these systems are battery powered, reducing power consumption is vital. In this report we give the properties of low-power design and techniques to exploit them on the architecture of the system. We focus on: minimizing capacitance, avoiding unnecessary and wasteful activity, and reducing voltage and frequency. We review energy reduction techniques in the architecture and design of a hand-held computer and the wireless communication system including error control, system decomposition, communication and MAC protocols, and low-power short range networks

The Design of a System Architecture for Mobile Multimedia Computers

This chapter discusses the system architecture of a portable computer, called Mobile Digital Companion, which provides support for handling multimedia applications energy efficiently. Because battery life is limited and battery weight is an important factor for the size and the weight of the Mobile Digital Companion, energy management plays a crucial role in the architecture. As the Companion must remain usable in a variety of environments, it has to be flexible and adaptable to various operating conditions. The Mobile Digital Companion has an unconventional architecture that saves energy by using system decomposition at different levels of the architecture and exploits locality of reference with dedicated, optimised modules. The approach is based on dedicated functionality and the extensive use of energy reduction techniques at all levels of system design. The system has an architecture with a general-purpose processor accompanied by a set of heterogeneous autonomous programmable modules, each providing an energy efficient implementation of dedicated tasks. A reconfigurable internal communication network switch exploits locality of reference and eliminates wasteful data copies

CASPR: Judiciously Using the Cloud for Wide-Area Packet Recovery

We revisit a classic networking problem -- how to recover from lost packets in the best-effort Internet. We propose CASPR, a system that judiciously leverages the cloud to recover from lost or delayed packets. CASPR supplements and protects best-effort connections by sending a small number of coded packets along the highly reliable but expensive cloud paths. When receivers detect packet loss, they recover packets with the help of the nearby data center, not the sender, thus providing quick and reliable packet recovery for latency-sensitive applications. Using a prototype implementation and its deployment on the public cloud and the PlanetLab testbed, we quantify the benefits of CASPR in providing fast, cost effective packet recovery. Using controlled experiments, we also explore how these benefits translate into improvements up and down the network stack

From growth to green growth -- a framework

Green growth is about making growth processes resource-efficient, cleaner and more resilient without necessarily slowing them. This paper aims at clarifying these concepts in an analytical framework and at proposing foundations for green growth. The green growth approach proposed here is based on (1) focusing on what needs to happen over the next 5-10 years before the world gets locked into patterns that would be prohibitively expensive and complex to modify and (2) reconciling the short and the long term, by offsetting short-term costs and maximizing synergies and economic co-benefits. This, in turn, increases the social and political acceptability of environmental policies. This framework identifies channels through which green policies can potentially contribute to economic growth. However, only detailed country- and context-specific analyses for each of these channels could reach firm conclusion regarding their actual impact on growth. Finally, the paper discusses the policies that can be implemented to capture these co-benefits and environmental benefits. Since green growth policies pursue a variety of goals, they are best served by a combination of instruments: price-based policies are important but are only one component in a policy tool-box that can also include norms and regulation, public production and direct investment, information creation and dissemination, education and moral suasion, or industrial and innovation policies.Environmental Economics&Policies,Climate Change Economics,Economic Theory&Research,Transport Economics Policy&Planning,Labor Policies

From Growth to Green Growth - a Framework

Green growth is about making growth resource-efficient, cleaner and more resilient without slowing it. This paper aims at clarifying this in an analytical framework and proposing foundations for green growth. This framework identifies channels through which green policies can potentially contribute to economic growth. Finally, the paper discusses the policies that can be implemented to capture co-benefits and environmental benefits. Since green growth policies pursue a variety of goals, they are best served by a combination of instruments: price-based policies are important but are only one component in a policy tool-box that can also include norms and regulation, public production and direct investment, information creation and dissemination, education and moral suasion, or industrial and innovation policies.