Communications systems technology assessment study. Volume 2: Results

The cost and technology characteristics are examined for providing special satellite services at UHF, 2.5 GHz, and 14/12 GHz. Considered are primarily health, educational, informational and emergency disaster type services. The total cost of each configuration including space segment, earth station, installation operation and maintenance was optimized to reduce the user's total annual cost and establish preferred equipment performance parameters. Technology expected to be available between now and 1985 is identified and comparisons made between selected alternatives. A key element of the study is a survey of earth station equipment updating past work in the field, providing new insight into technology, and evaluating production and test methods that can reduce costs in large production runs. Various satellite configurations were examined. The cost impact of rain attenuation at Ku-band was evaluated. The factors affecting the ultimate capacity achievable with the available orbital arc and available bandwidth were analyzed

Proceedings of the Second International Mobile Satellite Conference (IMSC 1990)

Presented here are the proceedings of the Second International Mobile Satellite Conference (IMSC), held June 17-20, 1990 in Ottawa, Canada. Topics covered include future mobile satellite communications concepts, aeronautical applications, modulation and coding, propagation and experimental systems, mobile terminal equipment, network architecture and control, regulatory and policy considerations, vehicle antennas, and speech compression

Propagation of Power Line Carrier Signals Through the Distribution Transformer.

In the wake of the governments 1989 Electricity act, privatisation reforms have urged the Electricity Supply Industry to enhance the capabilities of its current communication infrastructure . With this realisation , the possibilities of using the industries own distribution network as a communication medium has become a serious proposition. Although this may seem an innovative solution , the use of electrical distribution feeders for conveying information is not in fact new. However, recent advances in technology have provided solutions to the outstanding problem of attaining 'usable' data rates in the harsh power line environment. With this in mind, a power line telecommunications network seems a viable option for the electricity distribution companies. Unfortunately, a system which utilises both LV and MV networks remains presently unattainable , due to the unknown characteristics of the distribution transformer. Having highlighted the need to develop a 'through transformer' signalling system , the frequency characteristics of the distribution transformer have become of paramount interest. Although spread spectrum systems are gaining widespread acceptance, the high process gain required in adverse communication environments mitigates against high data rates. Investigations have demonstrated that an alternative strategy of lower frequency techniques is capable of maintaining a comparable integrity of communications. The following work catalogues the results and draws conclusions from research devoted to an investigation into the propagation of PLC frequency signals through distribution type transformers. From this analysis the viability of a 'through transformer' architecture may be assessed

Orbiting experiment for study of extended weightlessness Final report

Design, mission, and development of orbiting experiment to study extended weightlessness using monkeys and Apollo applications vehicl

Range Information Systems Management (RISM) Phase 1 Report

RISM investigated alternative approaches, technologies, and communication network architectures to facilitate building the Spaceports and Ranges of the future. RISM started by document most existing US ranges and their capabilities. In parallel, RISM obtained inputs from the following: 1) NASA and NASA-contractor engineers and managers, and; 2) Aerospace leaders from Government, Academia, and Industry, participating through the Space Based Range Distributed System Working Group (SBRDSWG), many of whom are also; 3) Members of the Advanced Range Technology Working Group (ARTWG) subgroups, and; 4) Members of the Advanced Spaceport Technology Working Group (ASTWG). These diverse inputs helped to envision advanced technologies for implementing future Ranges and Range systems that builds on today s cabled and wireless legacy infrastructures while seamlessly integrating both today s emerging and tomorrow s building-block communication techniques. The fundamental key is to envision a transition to a Space Based Range Distributed Subsystem. The enabling concept is to identify the specific needs of Range users that can be solved through applying emerging communication tec

Space Communications: Theory and Applications. Volume 3: Information Processing and Advanced Techniques. A Bibliography, 1958 - 1963

Annotated bibliography on information processing and advanced communication techniques - theory and applications of space communication

NASA Tech Briefs, November 1994

Topics: Advanced Manufacturing; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Reports