141,960 research outputs found

    Airport Surface Network Architecture Definition

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    Currently, airport surface communications are fragmented across multiple types of systems. These communication systems for airport operations at most airports today are based dedicated and separate architectures that cannot support system-wide interoperability and information sharing. The requirements placed upon the Communications, Navigation, and Surveillance (CNS) systems in airports are rapidly growing and integration is urgently needed if the future vision of the National Airspace System (NAS) and the Next Generation Air Transportation System (NGATS) 2025 concept are to be realized. To address this and other problems such as airport surface congestion, the Space Based Technologies Project s Surface ICNS Network Architecture team at NASA Glenn Research Center has assessed airport surface communications requirements, analyzed existing and future surface applications, and defined a set of architecture functions that will help design a scalable, reliable and flexible surface network architecture to meet the current and future needs of airport operations. This paper describes the systems approach or methodology to networking that was employed to assess airport surface communications requirements, analyze applications, and to define the surface network architecture functions as the building blocks or components of the network. The systems approach used for defining these functions is relatively new to networking. It is viewing the surface network, along with its environment (everything that the surface network interacts with or impacts), as a system. Associated with this system are sets of services that are offered by the network to the rest of the system. Therefore, the surface network is considered as part of the larger system (such as the NAS), with interactions and dependencies between the surface network and its users, applications, and devices. The surface network architecture includes components such as addressing/routing, network management, network performance and security

    How do I design a location-dependent application?

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    The generalisation of the Internet and the recent technological developments in embedded systems and wireless networks contribute to the realisation of a vision where access to information is possible at any moment and from anywhere. This is particularly attractive with information that is relevant to a specific geographic location. Applications that rely on location-based services to provide information to mobile users, or that support interaction with real devices in the user neighbourhood, are called location-dependent applications and enhance the relationship between mobile users and a specific geographic location. However, the design of such applications breaks with the existing paradigms and methodologies as the mobile devices and the wireless communication infrastructures have characteristics that are very different from those of desktop computers and wired communication systems. The Around architecture is an open and extensible framework for location-based services that allows network services to be associated with specific geographic locations. By using this architecture applications can select services that are relevant for specific locations. Within the context of the Around project we have developed a prototype system with multiple location-based services and an application that accesses these services to provide information related to a town transportation system. This paper reports on the design and development of this location-based application. Its design raised several new issues, going from the computational model to the interface paradigm, which are also discussed in this paper. The developed application is composed of several modules: a set of agents which are autonomous units with the knowledge necessary to select and use location-based services in a specific thematic area (e.g. transportation); an HTML output area based on a browser metaphor; and a location-context module responsible for determining the user context. The results show that an application architecture based on a modular approach turns to be very flexible as it becomes very easy to extend its functionality by simply adding or changing the agents that deal with each location-based service.Fundação para a Ciência e a Tecnologia (FCT) - (PRAXIS/P/EEI/14267/1998)

    NEWSKY - A concept for NEtWorking the SKY for civil aeronautical communications

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    In this paper, an overview of the NEWSKY project is given. This project is funded by the European Commission within the 6th framework program and will start in January 2007. The NEWSKY project is a feasibility study to clarify if it is possible to establish a heterogeneous network for aeronautical communications which is capable to integrate different communications systems as well as different applications into a single global aeronautical network. The envisaged applications comprise not only air-traffic control and management but also airline and passenger communications

    Experimental evaluation of an open source implementation of IPv6 GeoNetworking in VANETs

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    Conference is technically co-sponsored by IEEE Communications Society and co-organized by the Technical Sub-Committee on Vehicular Networks and Telematics (VNAT)International audienceISO TC204 and ETSI TC ITS are developing a set of standards for Cooperative ITS (Cooperative Intelligent transportation Systems) which will allow ITS stations i.e. vehicles, the road infrastructure and other peers reachable through the Internet to cooperate and exchange information with one another in order to enhance road safety, traffic efficiency and comfort for all road users. In situations where the exchange of information has to transit through the Internet, the use of IP, more specifically IPv6, is crucial and meets ITS needs for reliable and scalable communication capabilities in vehicular networks. An implementation of Cooperative ITS communication protocols is necessary to validate extensively the ETSI and ISO Coop- erative ITS standards. In this paper, we describe CarGeo6, an ongoing open-source implementation of the IPv6 GeoNetworking capabilities of the ITS station reference architecture based on the output of the GeoNet European Project. CarGeo6 combines IPv6 and GeoNetworking capabilities into a common protocol stack for the transmission of IPv6 packets into a given geographical area. This paper reports the validation process and the network performance evaluation of CarGeo6 as well as a comparison of these results with GeoNet results
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