630 research outputs found

    IP and ATM integration: A New paradigm in multi-service internetworking

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    ATM is a widespread technology adopted by many to support advanced data communication, in particular efficient Internet services provision. The expected challenges of multimedia communication together with the increasing massive utilization of IP-based applications urgently require redesign of networking solutions in terms of both new functionalities and enhanced performance. However, the networking context is affected by so many changes, and to some extent chaotic growth, that any approach based on a structured and complex top-down architecture is unlikely to be applicable. Instead, an approach based on finding out the best match between realistic service requirements and the pragmatic, intelligent use of technical opportunities made available by the product market seems more appropriate. By following this approach, innovations and improvements can be introduced at different times, not necessarily complying with each other according to a coherent overall design. With the aim of pursuing feasible innovations in the different networking aspects, we look at both IP and ATM internetworking in order to investigating a few of the most crucial topics/ issues related to the IP and ATM integration perspective. This research would also address various means of internetworking the Internet Protocol (IP) and Asynchronous Transfer Mode (ATM) with an objective of identifying the best possible means of delivering Quality of Service (QoS) requirements for multi-service applications, exploiting the meritorious features that IP and ATM have to offer. Although IP and ATM often have been viewed as competitors, their complementary strengths and limitations from a natural alliance that combines the best aspects of both the technologies. For instance, one limitation of ATM networks has been the relatively large gap between the speed of the network paths and the control operations needed to configure those data paths to meet changing user needs. IP\u27s greatest strength, on the other hand, is the inherent flexibility and its capacity to adapt rapidly to changing conditions. These complementary strengths and limitations make it natural to combine IP with ATM to obtain the best that each has to offer. Over time many models and architectures have evolved for IP/ATM internetworking and they have impacted the fundamental thinking in internetworking IP and ATM. These technologies, architectures, models and implementations will be reviewed in greater detail in addressing possible issues in integrating these architectures s in a multi-service, enterprise network. The objective being to make recommendations as to the best means of interworking the two in exploiting the salient features of one another to provide a faster, reliable, scalable, robust, QoS aware network in the most economical manner. How IP will be carried over ATM when a commercial worldwide ATM network is deployed is not addressed and the details of such a network still remain in a state of flux to specify anything concrete. Our research findings culminated with a strong recommendation that the best model to adopt, in light of the impending integrated service requirements of future multi-service environments, is an ATM core with IP at the edges to realize the best of both technologies in delivering QoS guarantees in a seamless manner to any node in the enterprise

    Supporting Cyber-Physical Systems with Wireless Sensor Networks: An Outlook of Software and Services

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    Sensing, communication, computation and control technologies are the essential building blocks of a cyber-physical system (CPS). Wireless sensor networks (WSNs) are a way to support CPS as they provide fine-grained spatial-temporal sensing, communication and computation at a low premium of cost and power. In this article, we explore the fundamental concepts guiding the design and implementation of WSNs. We report the latest developments in WSN software and services for meeting existing requirements and newer demands; particularly in the areas of: operating system, simulator and emulator, programming abstraction, virtualization, IP-based communication and security, time and location, and network monitoring and management. We also reflect on the ongoing efforts in providing dependable assurances for WSN-driven CPS. Finally, we report on its applicability with a case-study on smart buildings

    An Emulation Framework for Evaluating V2X Communications in C-ITS Applications

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    C-ITS enhances transportation systems with advanced communication tech, enabling vehicle-to-vehicle and vehicle-to-infrastructure data exchange for real-time decision-making. The thesis explores C-ITS concepts, DSRC, and C-V2X tech, and proposes a versatile C-ITS framework for app prototyping and communication evaluation. Real-world tests and simulations validate its potential to improve road safety and efficiency, suggesting integration opportunities for stakeholders and promoting a smarter, sustainable transportation ecosystem

    Segment Routing: a Comprehensive Survey of Research Activities, Standardization Efforts and Implementation Results

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    Fixed and mobile telecom operators, enterprise network operators and cloud providers strive to face the challenging demands coming from the evolution of IP networks (e.g. huge bandwidth requirements, integration of billions of devices and millions of services in the cloud). Proposed in the early 2010s, Segment Routing (SR) architecture helps face these challenging demands, and it is currently being adopted and deployed. SR architecture is based on the concept of source routing and has interesting scalability properties, as it dramatically reduces the amount of state information to be configured in the core nodes to support complex services. SR architecture was first implemented with the MPLS dataplane and then, quite recently, with the IPv6 dataplane (SRv6). IPv6 SR architecture (SRv6) has been extended from the simple steering of packets across nodes to a general network programming approach, making it very suitable for use cases such as Service Function Chaining and Network Function Virtualization. In this paper we present a tutorial and a comprehensive survey on SR technology, analyzing standardization efforts, patents, research activities and implementation results. We start with an introduction on the motivations for Segment Routing and an overview of its evolution and standardization. Then, we provide a tutorial on Segment Routing technology, with a focus on the novel SRv6 solution. We discuss the standardization efforts and the patents providing details on the most important documents and mentioning other ongoing activities. We then thoroughly analyze research activities according to a taxonomy. We have identified 8 main categories during our analysis of the current state of play: Monitoring, Traffic Engineering, Failure Recovery, Centrally Controlled Architectures, Path Encoding, Network Programming, Performance Evaluation and Miscellaneous...Comment: SUBMITTED TO IEEE COMMUNICATIONS SURVEYS & TUTORIAL

    Emulation platform design for multimedia applications over vehicular networks

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    Safety applications seems that will be decisive for a successful introduction to the automotive market for the vehicular networks. However, another kind of applications could be very helpful in order to reach the maximum number of equipped vehicles after market introduction, because can attract a greater number of users and facilitate a vehicular infrastructure investment because vehicular communication must provide business opportunities for Internet service providers to generate revenue. One of these kind of applications is live video streaming over vehicular networks. Video streaming is an attractive feature to many applications, such as emergency live video transmission, video on demand services, road-side video advertisement broadcasting and inter-vehicle video conversation. Test and evaluate implementations in a real testbed environment could be very costly and di cult in this kind of networks. Simulations are still commonly used as a first step in any development for vehicular networks research. Therefore, to test this kind of applications an emulation platform for multimedia applications over vehicular networks is presented in this article. We’ve studied the performance of video streaming services in a infrastructure environment over a highways taking special account in the losses that produces handovers during the communication caused by the network mobility

    Emulation platform design for multimedia applications over vehicular networks

    Get PDF
    Safety applications seems that will be decisive for a successful introduction to the automotive market for the vehicular networks. However, another kind of applications could be very helpful in order to reach the maximum number of equipped vehicles after market introduction, because can attract a greater number of users and facilitate a vehicular infrastructure investment because vehicular communication must provide business opportunities for Internet service providers to generate revenue. One of these kind of applications is live video streaming over vehicular networks. Video streaming is an attractive feature to many applications, such as emergency live video transmission, video on demand services, road-side video advertisement broadcasting and inter-vehicle video conversation. Test and evaluate implementations in a real testbed environment could be very costly and di cult in this kind of networks. Simulations are still commonly used as a first step in any development for vehicular networks research. Therefore, to test this kind of applications an emulation platform for multimedia applications over vehicular networks is presented in this article. We’ve studied the performance of video streaming services in a infrastructure environment over a highways taking special account in the losses that produces handovers during the communication caused by the network mobility

    Modeling the processing delays of Internet of Things nodes in the ns3 network simulator

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    As arquiteturas de hardware dos dispositivos orientados para a Internet of Things (IoT), ou Internet das Coisas, pressupõem a existência de restrições energéticas. O hardware e o software destes dispositivos são, por isso, projetados por forma a minimizar o consumo energético e, frequentemente, a capacidade de processamento e memória destes dispositivos são bastante limitados. Como consequência os tempos de execução de processos ou funções de código podem ter valores médios e variações elevados. Estas restrições têm um impacto grande, e até agora pouco estudado, no desempenho das redes de comunicações de objetos. Torna-se por isso importante estudar e modelizar o desempenho das funções de comunicações destes dispositivos. Nesta tese pretende-se fazer este estudo e desenvolver um módulo de software para o simulador de redes ns-3 que simule os tempos de processamento das funções de comunicação de múltiplas combinações de plataforma hardware/sistemas operativos reais

    Analysis of OSPFv3 in LEO satellite networks

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    Communication via satellite networks is under continuous research and development as it offers many advances over traditional terrestrial networks such as global coverage, but has a major drawback to be solved, the problem of point-to-point routing. In this work we have developed a satellite network emulator using Linux containers, which has allowed us to analyze the behavior of the IP routing protocol OSPFv3 in this type of networks. Specifically, its behavior has been analyzed in the Iridium constellation, which is widely known and used in this type of studies. For this purpose, we have used files of the topology of these networks over time generated with the HypatiaSeam orbital propagator, a modification of Hypatia made by the SeamSAT research group of the UPC. This project is part of a more global project whose objective is to be able to use a network of LEO satellites for communication between aircraft and airspace control centers. This would make it possible to centralize the different control centers, since it would not be necessary for aircraft to be in direct range to communicate with these centers, but thanks to the global coverage provided by these networks, they could communicate from anywhere in the world. Specifically, in this project we have developed an emulation platform that has allowed us to analyze the behavior of the OSPFv3 protocol to find optimal routes, i.e., shortest distance in terms of the cost function of the protocol. We will present the design and implementation of the emulation platform as well as the analysis of OSPFv3 performance in terms of protocol convergence time to topology changes, number of hops between a satellite and a ground station, delay and loss rate

    Internet Protocol (IP) Over Link-16

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    The purpose of Link- 16 is to exchange real-time tactical data among units of the United States and allied forces. Primary Link- 16 functions include exchange of friendly unit position and status data, fl%the dissemination of tactical surveillance track data, and the control/management of air, surface, and subsurface engagements. Because Link- 16 will play an integral role in fl% network-centric Joint Battlespace Infosphere (JBI), the performance of Internet Protocol version six (IPv6) and IP Security (IPSec) over Link-16 needs to be determined. Using OPNET modeling software to simulate a Link- 16 network, the investigation of this research revealed that the overhead from IPv6 and IPSec does not significantly affect end-to-end delay and effective throughput of the Link- 16 network. As long as the encryption and authentication protocols are preprocessed, these protocols add minimal amounts of latency overhead to the Link- 16 network. However, as the offered load is extended beyond the 90% level, the overhead from the IPSec extensions begins to have more of a negative effect on the End-to-End delay and throughput. Therefore, as the offered load increases beyond the 90% level, it begins to have a significant impact act on the performance of the Link- 16 network
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