Fred Burghardt

A low-power, lightweight unit to provide ubiquitous information access application and network support for InfoPad

Some of the most important trends in computer systems are the emerging use of multimedia Internet services, the popularity of portable computing, and the development of wireless data communications. The primary goal of the InfoPad project is to combine these trends to create a system that provides ubiquitous information access. The system is built around a low-power, lightweight wireless multimedia terminal that operates in indoor environments and supports a high density of users. The InfoPad system uses a number of innovative techniques to provide the high-bandwidth connectivity, portability, and user interface needed for this environment. The article describes the design, implementation, and evaluation of the software network and application services that support the InfoPad terminal. Special applications, type servers, and recognizers are developed for the InfoPad system. This software is designed to take advantage of the multimedia capabilities of the portable terminal and the additional computational resources available on the servers. The InfoNet system provides low-latency, high bandwidth connectivity between the computation and the portable terminal. It also provides the routing and handoff support that allows users to roam freely. The performance measurements of the system show that this design is a viable alternative, especially in the indoor environment.

PicoCube: a 1 cm 3 sensor node powered by harvested energy

The PicoCube is a 1 cm3 sensor node using harvested energy as its source of power. Operating at an average of only 6 uW for a tire-pressure application, the PicoCube represents a modular and integrated approach to the design of nodes for wireless sensor networks. It combines advanced ultra-low power circuit techniques with system-level power management. A simple packaging approach allows the modules comprising the node to fit into 1 cm3 in a reliable fashion.

InfoNet: The networking infrastructure of InfoPad

This paper provides an overview of InfoNet, the networking infrastructure for the InfoPad mobile computing system. First, the goals and architecture of InfoNet is defined. Next, the current implementation, performance measurements, and proxy connections are discussed. Finally, we present the future directions for InfoNet.

Design of wireless portable systems

The InfoPad project explores the infrastructure and devices required for portable wireless access to the national information infrastructure. The InfoPad model emphasizes high-bandwidth wireless connectivity and moves the computing power of the portable device into the backbone network, where we can provide not only full internet access, but increased computing power as well. By concentrating on I/O for the pad we reduce its cost, weight and power requirements, and increase the effective bandwidth through the greater error tolerance of I/O traffic such as video. We describe the InfoPad model, its infrastructure, and the results of the first prototype. This prototype proved the feasibility of the basic model and developed key technologies such as low-power design methodology and protocols for wireless connections. We also discuss the next generation InfoPad and our future plans.

Research challenges in wireless multimedia

The near future will bring the fusion of four rapidly evolving technologies: high speed networking and associated services, wireless communications, scaled integrated circuit technology, and multimedia-based applications. These new technologies will enable the access of multimedia data from network servers at any time and any place by light weight, low cost wireless terminals.

Powering and communication for OMNI: A distributed and modular closed-loop neuromodulation device

A distributed, modular, intelligent, and efficient neuromodulation device, called OMNI, is presented. It supports closed-loop recording and stimulation on 256 channels from up to 4 physically distinct neuromodulation modules placed in any configuration around the brain, hence offering the capability of addressing neural disorders that are presented at the network level. The specific focus of this paper is the communication and power distribution network that enables the modular and distributed nature of the device.

Connectivity Brokerage: From coexistence to collaboration

The explosive growth in the density of wirelessly connected devices and their traffic load is creating interference and gradually leading to a severe spectrum shortage. Approaches to address this challenge include dynamic spectrum allocation (cognitive radio) and pro-active interference mitigation strategies requiring coordination between heterogeneous networking technologies. This paper describes a modular and scalable methodology and architecture, called Connectivity Brokerage, that enables proactive co-existence and collaboration between diverse technologies, making joint optimization of the scarce spectrum resources possible.

Library support for connectivity brokerage

The growth of wireless communications has brought about the problem of interference. The realization of future wireless applications that require high data rate and service quality greatly depends on the alleviation of the interference problem. To this end, collaborative resource allocation between different wireless technologies has become an important technique. We have been designing a software architecture that we call “connectivity brokerage”, that will enable this collaboration. In this paper we explain the connectivity brokerage software architecture, and two parts of it; namely WAPI and distributed repository (CBDR) software libraries.