Experimental Evaluation of a Video Capture Board for Networked Workstations

This thesis examines the architectural issues in the design of a video capture board intended for use in multimedia videoconferencing. The major issues examined are: Control of reception and transmission of multimedia video streams, (i) Quality of service and service provision (ii) Compression requirements and solutions (iii) Data buffering and card connection strategies (iv) Handling multiple video streams Results of measurements for prototype boards designed and constructed at Penn are also given

Power Management in Mobile Computing (a Survey)

Rapid advances in technology have resulted in laptop (mobile) computers with performance and features comparable to desktop (stationary) machines. Advances in rechargeable battery technology have failed to keep pace, decreasing the usefulness of mobile computers and portable wireless devices. Several methods of power management can be used to prolong the battery life of a mobile computer. We provide a detailed analysis of power consumption typically encountered in a networked laptop computer and the power management methods currently used. We also outline some novel proposed power management methods

VENUS: A Virtual Environment Network Using Satellites

Virtual environment (VE) designs have evolved from text-based to immersive graphical systems. The next logical step of this evolution is to have a fully immersive environment in which thousands of widely distributed users will be able to move around and interact. This requires a VE architecture that can scale well for a large number of participants while providing the necessary support for quality of service, security and flexibility. Current VE architectures are unable to fully meet these requirements and a new network/protocol architecture is needed. The VENUS approach addresses these problems by creating a network architecture which is scalable and flexible. We define a new architecture consisting of a transmit-only satellite/server and bi-directional links which will be capable of sustaining a wide-area virtual environment. We then offer the preliminary results of our experiments

VENUS: A Virtual Environment Network Using Satellites

this paper, N is used to indicate the number of users in the system. In the worst case, each of the N users sends out an update message to the other N - 1 users, resulting in O(

Power Management of Permanent Storage in Mobile Computers

Mobile 1 computer usage is increasing rapidly and laptops now come equipped with the latest microprocessors, color displays, large disks and other energy-intensive devices. Unfortunately, the batteries that power all this portability are lagging behind in their ability to meet these increasing power requirements. As a result mobile computers suffer from short battery life and require frequent recharging. Three subsystems---the display, permanent storage and microprocessor---account for over 90% of the total power usage in a mobile computer. In this paper, we will focus on the storage subsystem, which can consume up to 30% of total system power. We will look at several methods of optimizing permanent storage on mobile computers to reduce power consumption and extend battery life while maintaining current performance levels. 1 In this paper, the term mobile computer is used for the current generation of laptop/notebook computers as well as future portables that will include wireless c..

The Power Broker: intelligent power management for mobile computers

Technology has improved processor speed and memory densities at exponential rates. Rapid advances in portable computing have resulted in laptop computers with performance and features comparable to their desktop counterparts. Battery technology has failed to keep pace, decreasing the usefulness of mobile computers and portable wireless devices. We provide a detailed analysis of power consumption typically encountered in a networked laptop computer and the power management methods currently used. We then show how interaction between independent power consumers results in inefficient use of energy resources and propose the Power Broker as a means for orchestrating energy use with the goal of extending battery life. The Power Broker’s resource management algorithms exploit an abundant resource (CPU power) to conserve a scarce one (battery energy).

Power Management in Mobile Computing

Rapid advances in technology have resulted in laptop (mobile) computers with performance and features comparable to desktop (stationary) machines. Advances in rechargeable battery technology have failed to keep pace, decreasing the usefulness of mobile computers and portable wireless devices. Several methods of power management can be used to prolong the battery life of a mobile computer. We provide a detailed analysis of power consumption typically encountered in a networked laptop computer and the power management methods currently used. We also outline some novel proposed power management methods. 1 Introduction Laptop computers have often served as portable word processors or game machines. Such machines were generally two or more generations behind desktop computers in terms of processing power, features and performance. Limitations in display and miniaturization technology prevented laptops from being able to compete with desktops as "real" (i.e. full featured) computers. Recent..

Evaluation Of A Video Capture Board For Networked Workstations

This thesis examines the architectural issues in the design of a video capture board intended for use in multimedia videoconferencing. The major issues examined are: ffl Control of reception and transmission of multimedia video streams ffl Quality of service and service provision ffl Compression requirements and solutions ffl Data buffering and card connection strategies ffl Handling multiple video streams Results of measurements for prototype boards designed and constructed at Penn are also given. ii Acknowledgements I would like thank Jonathan Smith for his support and guidance throughout the project. And Brendan Traw, Alex Doyle and Al Broscius for their invaluable assistance in the design and debugging of the video boards. Thanks also to Supun Samarasekara and Gordon Mcclennen for their help in writing part of the X code. AURORA is a joint research effort undertaken by Bell Atlantic, Bellcore, IBM Research, MIT, MCI, NYNEX, and Penn. AURORA is sponsored as part of the NSF/DARPA ..

FPGA Viruses

. Programmable logic is widely used, for applications ranging from field-upgradable subsystems to advanced uses such as reconfigurable computing platforms which are modifiable at run-time. Users can thus implement algorithms which are largely executed by a general-purpose CPU, but may be selectively accelerated with special purpose hardware. In this paper, we show that programmable logic devices unfortunately open another avenue for malicious users to implement the hardware analogue of a computer virus. We begin the paper with an outline of the general properties of FPGAs that create risks. We then explain how to exploit these risks, and demonstrate through directed experiments that they are exploitable even in the absence of detailed layout information. We prove our point by demonstrating the first known FPGA virus and its effect on the current absorbed by the device, namely that the device is destroyed. We close by outlining possible methods of defense and point out the similarities ..