1,952 research outputs found

    Adoption of vehicular ad hoc networking protocols by networked robots

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    This paper focuses on the utilization of wireless networking in the robotics domain. Many researchers have already equipped their robots with wireless communication capabilities, stimulated by the observation that multi-robot systems tend to have several advantages over their single-robot counterparts. Typically, this integration of wireless communication is tackled in a quite pragmatic manner, only a few authors presented novel Robotic Ad Hoc Network (RANET) protocols that were designed specifically with robotic use cases in mind. This is in sharp contrast with the domain of vehicular ad hoc networks (VANET). This observation is the starting point of this paper. If the results of previous efforts focusing on VANET protocols could be reused in the RANET domain, this could lead to rapid progress in the field of networked robots. To investigate this possibility, this paper provides a thorough overview of the related work in the domain of robotic and vehicular ad hoc networks. Based on this information, an exhaustive list of requirements is defined for both types. It is concluded that the most significant difference lies in the fact that VANET protocols are oriented towards low throughput messaging, while RANET protocols have to support high throughput media streaming as well. Although not always with equal importance, all other defined requirements are valid for both protocols. This leads to the conclusion that cross-fertilization between them is an appealing approach for future RANET research. To support such developments, this paper concludes with the definition of an appropriate working plan

    Hybrid Satellite-Terrestrial Communication Networks for the Maritime Internet of Things: Key Technologies, Opportunities, and Challenges

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    With the rapid development of marine activities, there has been an increasing number of maritime mobile terminals, as well as a growing demand for high-speed and ultra-reliable maritime communications to keep them connected. Traditionally, the maritime Internet of Things (IoT) is enabled by maritime satellites. However, satellites are seriously restricted by their high latency and relatively low data rate. As an alternative, shore & island-based base stations (BSs) can be built to extend the coverage of terrestrial networks using fourth-generation (4G), fifth-generation (5G), and beyond 5G services. Unmanned aerial vehicles can also be exploited to serve as aerial maritime BSs. Despite of all these approaches, there are still open issues for an efficient maritime communication network (MCN). For example, due to the complicated electromagnetic propagation environment, the limited geometrically available BS sites, and rigorous service demands from mission-critical applications, conventional communication and networking theories and methods should be tailored for maritime scenarios. Towards this end, we provide a survey on the demand for maritime communications, the state-of-the-art MCNs, and key technologies for enhancing transmission efficiency, extending network coverage, and provisioning maritime-specific services. Future challenges in developing an environment-aware, service-driven, and integrated satellite-air-ground MCN to be smart enough to utilize external auxiliary information, e.g., sea state and atmosphere conditions, are also discussed

    Infraestrutura de beira de estrada para apoio a sistemas cooperativos e inteligentes de transportes

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    The growing need of mobility along with the evolution of the automotive industry and the massification of the personal vehicle amplifies some of the road-related problems such as safety and traffic congestion. To mitigate such issues, the evolution towards cooperative communicating technologies and autonomous systems is considered a solution to overcome the human physical limitations and the limited perception horizon of on-board sensors. Short-range vehicular communications such as Vehicle-to-Vehicle or Vehicle-to-Infrastructure (ETSI ITS-G5) in conjunction with long-range cellular communications (LTE,5G) and standardized messages, emerge as viable solutions to amplify the benefits that standalone technologies can bring to the road environment, by covering a wide array of applications and use cases. In compliance with the standardization work from European Telecommunications Standards Institute (ETSI), this dissertation describes the implementation of the collective perception service in a real road infrastructure to assist the maneuvers of autonomous vehicles and provide information to a central road operator. This work is focused on building standardized collective perception messages (CPM) by retrieving information from traffic classification radars (installed in the PASMO project) for local dissemination using ETSI ITS-G5 radio technology and creating a redundant communication channel between the road infrastructure and a central traffic control centre, located at the Instituto de TelecomunicaƧƵes - Aveiro, taking advantage of cellular, point-to-point radio links and optical fiber communications. The output of the messages are shown to the user by a mobile application. The service is further improved by building an algorithm for optimizing the message dissemination to improve channel efficiency in more demanding scenarios. The results of the experimental tests showed that the time delay between the production event of the collective perception message and the reception by other ITS stations is within the boundaries defined by ETSI standards. Moreover, the algorithm for message dissemination also shows to increase radio channel efficiency by limiting the number of objects disseminated by CPM messages. The collective perception service developed and the road infrastructure are therefore, a valuable asset to provide useful information for improving road safety and fostering the deployment of intelligent cooperative transportation systems.A crescente necessidade de mobilidade em paralelo com a evoluĆ§Ć£o da indĆŗstria automĆ³vel e com a massificaĆ§Ć£o do uso de meios de transportes pessoais, tĆŖm vindo a amplificar alguns problemas dos transportes rodoviĆ”rios, tais como a seguranƧa e o congestionamento do trĆ”fego. Para mitigar estas questƵes, a evoluĆ§Ć£o das tecnologias de comunicaĆ§Ć£o cooperativas e dos sistemas autĆ³nomos Ć© vista como uma potencial soluĆ§Ć£o para ultrapassar limitaƧƵes dos condutores e do horizonte de perceĆ§Ć£o dos sensores veĆ­culares. ComunicaƧƵes de curto alcance, tais como VeĆ­culo-a-VeĆ­culo ou VeĆ­culo-a-Infrastrutura (ETSI ITS-G5), em conjunto com comunicaƧƵes mĆ³veis de longo alcance (LTE,5G) e mensagens padrĆ£o, emergem como soluƧƵes viĆ”veis para amplificar todos os beneficios que tecnologias independentes podem trazer para o ambiente rodoviĆ”rio, cobrindo um grande leque de aplicaƧƵes e casos de uso da estrada. Em conformidade com o trabalho de padronizaĆ§Ć£o da European Telecommunications Standards Institute, esta dissertaĆ§Ć£o descreve a implementaĆ§Ć£o do serviƧo de perceĆ§Ć£o coletiva, numa infrastrutura rodoviĆ”ria real, para suporte a manobras de veĆ­culos autĆ³nomos e para fornecer informaƧƵes aos operadores de estradas. Este trabalho foca-se na construĆ§Ć£o de mensagens de perceĆ§Ć£o coletiva a partir de informaĆ§Ć£o gerada por radares de classificaĆ§Ć£o de trĆ”fego (instalados no Ć¢mbito do projeto PASMO) para disseminaĆ§Ć£o local usando a tecnologia rĆ”dio ETSI ITS-G5 e criando um canal de comunicaĆ§Ć£o redundante entre a infraestrutura rodĆ³viaria e um centro de controlo de trĆ”fego localizado no Instituto de TelecomunicaƧƵes - Aveiro, usando para isso: redes mĆ³veis, ligaƧƵes rĆ”dio ponto a ponto e fibra Ć³tica. O conteĆŗdo destas messagens Ć© mostrado ao utilizador atravĆ©s de uma aplicaĆ§Ć£o mĆ³vel. O serviƧo Ć© ainda melhorado, tendo-se para tal desenvolvido um algoritmo de otimizaĆ§Ć£o de disseminaĆ§Ć£o das mensagens, tendo em vista melhorar a eficiĆŖncia do canal de transmissĆ£o em cenĆ”rios mais exigentes. Os resultados dos testes experimentais efetuados revelaram que o tempo de atraso entre o evento de produĆ§Ć£o de uma mensagem de perceĆ§Ć£o coletiva e a receĆ§Ć£o por outra estaĆ§Ć£o ITS, usando comunicaƧƵes ITS-G5, se encontra dentro dos limites definidos pelos padrƵes da ETSI. AlĆ©m disso, o algoritmo para disseminaĆ§Ć£o de mensagens tambĆ©m mostrou aumentar a eficiĆŖncia do canal de rĆ”dio, limitando o nĆŗmero de objetos disseminados pelas mesmas. Assim, o serviƧo de perceĆ§Ć£o coletiva desenvolvido poderĆ” ser uma ferramenta valiosa, contribuindo para o aumento da seguranƧa rodĆ³viaria e para a disseminaĆ§Ć£o da utilizaĆ§Ć£o dos sistemas cooperativos de transporte inteligente.Mestrado em Engenharia EletrĆ³nica e TelecomunicaƧƵe

    Feudalistic Platooning: Subdivide Platoons, Unite Networks, and Conquer Efficiency and Reliability

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    Cooperative intelligent transportation systems (C-ITSs) such as platooning rely on a robust and timely network that may not always be available in sufficient quality. Out of the box hybrid networks only partly eliminate shortcomings: mutual interference avoidance, data load balancing, and data dissemination must be sophisticated. Lacking network quality may lead to safety bottlenecks that require that the distance between the following vehicles be increased. However, increasing gaps result in efficiency loss and additionally compromise safety as the platoon is split into smaller parts by traffic: maneuvers, e.g., cut-in maneuvers bear safety risks, and consequently lower efficiency even further. However, platoons, especially if they are very long, can negatively affect the flow of traffic. This mainly applies on entry or exit lanes, on narrow lanes, or in intersection areas: automated and non-automated vehicles in traffic do affect each other and are interdependent. To account for varying network quality and enable the coexistence of non-automated and platooned traffic, we present in this paper a new concept of platooning that unites ad hocā€”in form of IEEE 802.11pā€”and cellular communication: feudalistic platooning. Platooned vehicles are divided into smaller groups, inseparable by surrounding traffic, and are assigned roles that determine the communication flow between vehicles, other groups and platoons, and infrastructure. Critical vehicle data are redundantly sent while the ad hoc network is only used for this purpose. The remaining data are sentā€”relying on cellular infrastructure once it is availableā€”directly between vehicles with or without the use of network involvement for scheduling. The presented approach was tested in simulations using Omnet++ and Simulation of Urban Mobility (SUMO)

    A survey on vehicular communication for cooperative truck platooning application

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    Platooning is an application where a group of vehicles move one after each other in close proximity, acting jointly as a single physical system. The scope of platooning is to improve safety, reduce fuel consumption, and increase road use efficiency. Even if conceived several decades ago as a concept, based on the new progress in automation and vehicular networking platooning has attracted particular attention in the latest years and is expected to become of common implementation in the next future, at least for trucks.The platoon system is the result of a combination of multiple disciplines, from transportation, to automation, to electronics, to telecommunications. In this survey, we consider the platooning, and more specifically the platooning of trucks, from the point of view of wireless communications. Wireless communications are indeed a key element, since they allow the information to propagate within the convoy with an almost negligible delay and really making all vehicles acting as one. Scope of this paper is to present a comprehensive survey on connected vehicles for the platooning application, starting with an overview of the projects that are driving the development of this technology, followed by a brief overview of the current and upcoming vehicular networking architecture and standards, by a review of the main open issues related to wireless communications applied to platooning, and a discussion of security threats and privacy concerns. The survey will conclude with a discussion of the main areas that we consider still open and that can drive future research directions.(c) 2022 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

    Street Smart in 5G : Vehicular Applications, Communication, and Computing

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    Recent advances in information technology have revolutionized the automotive industry, paving the way for next-generation smart vehicular mobility. Specifically, vehicles, roadside units, and other road users can collaborate to deliver novel services and applications that leverage, for example, big vehicular data and machine learning. Relatedly, fifth-generation cellular networks (5G) are being developed and deployed for low-latency, high-reliability, and high bandwidth communications. While 5G adjacent technologies such as edge computing allow for data offloading and computation at the edge of the network thus ensuring even lower latency and context-awareness. Overall, these developments provide a rich ecosystem for the evolution of vehicular applications, communications, and computing. Therefore in this work, we aim at providing a comprehensive overview of the state of research on vehicular computing in the emerging age of 5G and big data. In particular, this paper highlights several vehicular applications, investigates their requirements, details the enabling communication technologies and computing paradigms, and studies data analytics pipelines and the integration of these enabling technologies in response to application requirements.Peer reviewe

    Evaluating the user experience of acoustic data transmission A study of sharing data between mobile devices using sound

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    Users of smart devices frequently need to exchange data with people nearby to them. Yet despite the availability of various communication methods, data exchange between co-located devices is often complicated by technical and user experience barriers. A potential solution to these issues is the emerging technology of device-to-device acoustic data transmission. In this work, we investigate the medium-specific properties of sound as a data exchange mechanism, and question how these contribute to the user experience of sharing data. We present a user study comparing three wireless communication technologies (acoustic data transmission, QR codes and Bluetooth), when used for a common and familiar scenario: peer-to-peer sharing of contact information. Overall, the results show that acoustic data transmission provides a rapid means of transferring data (mean transaction time of 2.4 s), in contrast to Bluetooth (8.3 s) and QR (6.3 s), whilst requiring minimal physical effort and user coordination. All QR code transactions were successful on the first attempt; however, some acoustic (5.6%) and Bluetooth (16.7%) transactions required multiple attempts to successfully share a contact. Participants also provided feedback on their user experience via surveys and semi-structured interviews. Perceived transaction time, physical effort, and connectivity issues. Specifically, users expressed frustration with Bluetooth due to device selection issues, and with QR for the physical coordination required to scan codes. The findings indicate that acoustic data transmission has unique advantages in facilitating information sharing and interaction between co-located users

    Aeronautics and space report of the President, 1982 activities

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    Achievements of the space program are summerized in the area of communication, Earth resources, environment, space sciences, transportation, aeronautics, and space energy. Space program activities of the various deprtments and agencies of the Federal Government are discussed in relation to the agencies' goals and policies. Records of U.S. and world spacecraft launchings, successful U.S. launches for 1982, U.S. launched applications and scientific satellites and space probes since 1975, U.S. and Soviet manned spaceflights since 1961, data on U.S. space launch vehicles, and budget summaries are provided. The national space policy and the aeronautical research and technology policy statements are included
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