2,160 research outputs found

    Ethernet - a survey on its fields of application

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    During the last decades, Ethernet progressively became the most widely used local area networking (LAN) technology. Apart from LAN installations, Ethernet became also attractive for many other fields of application, ranging from industry to avionics, telecommunication, and multimedia. The expanded application of this technology is mainly due to its significant assets like reduced cost, backward-compatibility, flexibility, and expandability. However, this new trend raises some problems concerning the services of the protocol and the requirements for each application. Therefore, specific adaptations prove essential to integrate this communication technology in each field of application. Our primary objective is to show how Ethernet has been enhanced to comply with the specific requirements of several application fields, particularly in transport, embedded and multimedia contexts. The paper first describes the common Ethernet LAN technology and highlights its main features. It reviews the most important specific Ethernet versions with respect to each application field’s requirements. Finally, we compare these different fields of application and we particularly focus on the fundamental concepts and the quality of service capabilities of each proposal

    Advanced manned space flight simulation and training: An investigation of simulation host computer system concepts

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    The findings of a preliminary investigation by Southwest Research Institute (SwRI) in simulation host computer concepts is presented. It is designed to aid NASA in evaluating simulation technologies for use in spaceflight training. The focus of the investigation is on the next generation of space simulation systems that will be utilized in training personnel for Space Station Freedom operations. SwRI concludes that NASA should pursue a distributed simulation host computer system architecture for the Space Station Training Facility (SSTF) rather than a centralized mainframe based arrangement. A distributed system offers many advantages and is seen by SwRI as the only architecture that will allow NASA to achieve established functional goals and operational objectives over the life of the Space Station Freedom program. Several distributed, parallel computing systems are available today that offer real-time capabilities for time critical, man-in-the-loop simulation. These systems are flexible in terms of connectivity and configurability, and are easily scaled to meet increasing demands for more computing power

    A Time-Triggered Constraint-Based Calculus for Avionic Systems

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    The Integrated Modular Avionics (IMA) architec- ture and the Time-Triggered Ethernet (TTEthernet) network have emerged as the key components of a typical architecture model for recent civil aircrafts. We propose a real-time constraint-based calculus targeted at the analysis of such concepts of avionic embedded systems. We show our framework at work on the modelisation of both the (IMA) architecture and the TTEthernet network, illustrating their behavior by the well-known Flight Management System (FMS)

    Research and technology goals and objectives for Integrated Vehicle Health Management (IVHM)

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    Integrated Vehicle Health Management (IVHM) is defined herein as the capability to efficiently perform checkout, testing, and monitoring of space transportation vehicles, subsystems, and components before, during, and after operational This includes the ability to perform timely status determination, diagnostics, and prognostics. IVHM must support fault-tolerant response including system/subsystem reconfiguration to prevent catastrophic failures; and IVHM must support the planning and scheduling of post-operational maintenance. The purpose of this document is to establish the rationale for IVHM and IVHM research and technology planning, and to develop technical goals and objectives. This document is prepared to provide a broad overview of IVHM for technology and advanced development activities and, more specifically, to provide a planning reference from an avionics viewpoint under the OAST Transportation Technology Program Strategic Plan

    The Political Economy of Industrial Policy in China: The Case of Aircraft Manufacturing

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    Since 1960, only one new country, Brazil, has succeeded in delivering more than one civil jet per month. Otherwise, all the countries now offering world-class planes were established in aviation by the end of World War I. This being said, low-cost producers within several of the newly emerging markets have already acquired front-end manufacturing expertise as a direct result of industrial offset contracts and/or other forms of technology transfer. In all such cases, government intervention, notably through state ownership, has been predominant, but failures have been numerous in view of the difficulty of aligning ownership structure to financial, managerial, and technological requirements and of garnering the support of domestic interest groups. In this paper the focus is China’s efforts to build a world-class aircraft manufacturing industry. In the first half of the 1990s the potential of the Chinese industry to mount a competitive challenge to Western aircraft builders was largely discounted. Nowadays, as China strives to bear the ARJ-21 project to execution and even considers entering the market for wide-bodies, the threat is taken more seriously. The growth in the Chinese air transport market has reinforced the bargaining power of national aircraft producers and authorities are giving priority to building science and technology capacity in this area. Progress in creating military/civilian synergies has proven much more modest – especially when compared to the shipbuilding industry – and better coordination in the overall industry comes a distant fourth in the explanations’ peaking order.http://deepblue.lib.umich.edu/bitstream/2027.42/40165/3/wp779.pd

    Secure Space Mesh Networking

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    Innoflight’s Secure Space Mesh Networking development and prototyping efforts started at its incorporation over 15 years ago with a vision of establishing end-to-end Internet Protocol (IP) connectivity in and through space. A number of space industry trends have accelerated the demand for space networking: (a) the widespread adoption of enterprise-grade and cloud-based, IP-centric ground system architectures; (b) the accelerated growth of both commercial and government proliferated Low Earth Orbit (pLEO) constellations leveraging small satellites (SmallSats); (c) the maturation, miniaturization and commoditization of high-speed Radio Frequency (RF), Free Space Optical (FSO) Inter-Satellite Links (ISLs), and high-performance flight processors for aforementioned SmallSats; and (d) the need for All-Domain Operations (ADO) seamlessly and autonomously integrating space, airborne, terrestrial, maritime and underwater networks. Furthermore, data encryption, for reasons of either National Security or monetized mission data protection, creates additional challenges to effectively switch/route and encrypt/decrypt ciphertext data across a mesh network. Lastly, with the projection of multiple and multi-national pLEO constellations, it is critical to negotiate link security real-time for dynamic, trusted nodes, and prevent inadvertent or intentional networking with unknown/untrusted nodes. Innoflight will discuss the aforementioned relevant space industry trends and commercial and government initiatives, including DARPA (Defense Advanced Research Projects Agency) Blackjack and Space Development Agency’s (SDA) National Defense Space Architecture (NDSA), and then identify the technical challenges for secure space mesh networking and decompose these challenges with two popular frameworks: (a) the individual layers, especially Layer 2 (data/link layer) and Layer 3 (network layer), within the Open Systems Interconnection (OSI) model; and (b) the control and data planes within the Software Defined Networking (SDN) model. Innoflight will present its development and prototyping efforts, specific to these challenges, including recent work funded under a 2019 Space Pitch Day award and leveraging its general-purpose processing and networking CFC-400X platform, and conclude by identifying remaining gaps: including technical, commercial and policy; to fully realize interoperable secure space mesh networking.
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