Market scenarios and alternative administrative frameworks for US educational satellite systems

Costs and benefits of developing an operational educational satellite system in the U.S. are analyzed. Scenarios are developed for each educational submarket and satellite channel and ground terminal requirements for a large-scale educational telecommunications system are estimated. Alternative organizational frameworks for such a system are described

System data communication structures for active-control transport aircraft, volume 2

The application of communication structures to advanced transport aircraft are addressed. First, a set of avionic functional requirements is established, and a baseline set of avionics equipment is defined that will meet the requirements. Three alternative configurations for this equipment are then identified that represent the evolution toward more dispersed systems. Candidate communication structures are proposed for each system configuration, and these are compared using trade off analyses; these analyses emphasize reliability but also address complexity. Multiplex buses are recognized as the likely near term choice with mesh networks being desirable for advanced, highly dispersed systems

UNPLUGGED CITY Escaping from Global Networks and Flows Trap? New Geographies of Logistics :: Urban and Regional Implications

The urban and regional influence of contemporary passengers, goods and information traffic within the new global economy based on knowledge and logistics, and the physical structures that shape the networks (harbours, airports, train stations, motorways) are assumed as capitally important. Nevertheless, so far, the impact of these dynamics is much more attached to hierarchical processes of socio-spatial fragmentation-segmentation-polarization rather than balanced re-distributive systems. Global connectivity has as much strengths as threats, and the integration within the new production, consumption and distribution geographies generates as much opportunities as irreversible mutations. Unplugged City is presented as an incursion on connectivity and accessibility, exploring the strengths and threats derived from the management of logistics and freight transport flows within the frame of the so-called “catch-up†economy. The Trans-European Transport Network Plan (TEN-T) will be on focus as the main policy-making framework behind the new geographical transformation in Europe. The importance of the exponential growing freight transport and logistic sector has been exposed as a key factor to understand the bases of current globalisation. The sharp changes generated by the dropping of transport cost in patterns of production-consumption-distribution geographies have to be contrasted with deep transformations of labour market, linkages between transport and industrial location and new network models. What is close is just what is cheap. Distances nowadays are no measured in kilometres or hours but in Euros, imposing a new logic for the global geographic structure. Regions with better access to locations of input materials and markets are assumed to be more productive, more competitive and hence more successful than more peripheral and isolated regions. But this hypothesis has to be urgently reformulated, contrasting transport policies with quantitative research and the appraisal of real socio-economic impact of the new transport geographies. The assumed idea of connectivity as pure benefiting will be critically discussed as a much complex phenomena. Corridors are fostering the survival of core regional centres meanwhile a growing regional imbalance is monitored; regions that still have to deal with environmental, budgetary and indirect issues derived from the management of these flows.

Cost Effective Routing Implementations for On-chip Networks

Arquitecturas de múltiples núcleos como multiprocesadores (CMP) y soluciones multiprocesador para sistemas dentro del chip (MPSoCs) actuales se basan en la eficacia de las redes dentro del chip (NoC) para la comunicación entre los diversos núcleos. Un diseño eficiente de red dentro del chip debe ser escalable y al mismo tiempo obtener valores ajustados de área, latencia y consumo de energía. Para diseños de red dentro del chip de propósito general se suele usar topologías de malla 2D ya que se ajustan a la distribución del chip. Sin embargo, la aparición de nuevos retos debe ser abordada por los diseñadores. Una mayor probabilidad de defectos de fabricación, la necesidad de un uso optimizado de los recursos para aumentar el paralelismo a nivel de aplicación o la necesidad de técnicas eficaces de ahorro de energía, puede ocasionar patrones de irregularidad en las topologías. Además, el soporte para comunicación colectiva es una característica buscada para abordar con eficacia las necesidades de comunicación de los protocolos de coherencia de caché. En estas condiciones, un encaminamiento eficiente de los mensajes se convierte en un reto a superar. El objetivo de esta tesis es establecer las bases de una nueva arquitectura para encaminamiento distribuido basado en lógica que es capaz de adaptarse a cualquier topología irregular derivada de una estructura de malla 2D, proporcionando así una cobertura total para cualquier caso resultado de soportar los retos mencionados anteriormente. Para conseguirlo, en primer lugar, se parte desde una base, para luego analizar una evolución de varios mecanismos, y finalmente llegar a una implementación, que abarca varios módulos para alcanzar el objetivo mencionado anteriormente. De hecho, esta última implementación tiene por nombre eLBDR (effective Logic-Based Distributed Routing). Este trabajo cubre desde el primer mecanismo, LBDR, hasta el resto de mecanismos que han surgido progresivamente.Rodrigo Mocholí, S. (2010). Cost Effective Routing Implementations for On-chip Networks [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/8962Palanci

Survey of Inter-satellite Communication for Small Satellite Systems: Physical Layer to Network Layer View

Small satellite systems enable whole new class of missions for navigation, communications, remote sensing and scientific research for both civilian and military purposes. As individual spacecraft are limited by the size, mass and power constraints, mass-produced small satellites in large constellations or clusters could be useful in many science missions such as gravity mapping, tracking of forest fires, finding water resources, etc. Constellation of satellites provide improved spatial and temporal resolution of the target. Small satellite constellations contribute innovative applications by replacing a single asset with several very capable spacecraft which opens the door to new applications. With increasing levels of autonomy, there will be a need for remote communication networks to enable communication between spacecraft. These space based networks will need to configure and maintain dynamic routes, manage intermediate nodes, and reconfigure themselves to achieve mission objectives. Hence, inter-satellite communication is a key aspect when satellites fly in formation. In this paper, we present the various researches being conducted in the small satellite community for implementing inter-satellite communications based on the Open System Interconnection (OSI) model. This paper also reviews the various design parameters applicable to the first three layers of the OSI model, i.e., physical, data link and network layer. Based on the survey, we also present a comprehensive list of design parameters useful for achieving inter-satellite communications for multiple small satellite missions. Specific topics include proposed solutions for some of the challenges faced by small satellite systems, enabling operations using a network of small satellites, and some examples of small satellite missions involving formation flying aspects.Comment: 51 pages, 21 Figures, 11 Tables, accepted in IEEE Communications Surveys and Tutorial

C-MOS array design techniques: SUMC multiprocessor system study

The current capabilities of LSI techniques for speed and reliability, plus the possibilities of assembling large configurations of LSI logic and storage elements, have demanded the study of multiprocessors and multiprocessing techniques, problems, and potentialities. Evaluated are three previous systems studies for a space ultrareliable modular computer multiprocessing system, and a new multiprocessing system is proposed that is flexibly configured with up to four central processors, four 1/0 processors, and 16 main memory units, plus auxiliary memory and peripheral devices. This multiprocessor system features a multilevel interrupt, qualified S/360 compatibility for ground-based generation of programs, virtual memory management of a storage hierarchy through 1/0 processors, and multiport access to multiple and shared memory units

Regionalizing telecommunications reform in West Africa

In recent years, there has been an increasing recognition that significant welfare gains could be realized through deep forms of regional integration which entail harmonization of legal, regulatory and institutional frameworks. Reforms that reduce cross-border transaction costs and improve the performance of “backbone” infrastructure services are arguably even more important for the creation of an open, unified regional economic space than trade policy reforms narrowly defined. This paper assesses the potential gains from regionalized telecommunications policy in West Africa. To this end, the paper: (i) discusses how regional cooperation can overcome national limits in technical expertise, enhance the capacity of nations credibly to commit to stable regulatory policy, and ultimately facilitate infrastructure investment in the region; (ii) identifies trade-distorting regulations that inhibit opportunities for regional trade and economic development, and so are good candidates for regional trade negotiations to reduce indirect trade barriers; and (iii) describes substantive elements of a harmonized regional regulatory policy that can deliver immediate performance benefits.E-Business,Environmental Economics&Policies,ICT Policy and Strategies,Transport Economics Policy&Planning,Emerging Markets