2,619 research outputs found

    Satellite Communications: Impact on Developing Economies

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    Access to information and communication infrastructure greatly enhances economic growth. When a reliable and affordable medium for information exchange is available, previously unanticipated developments ensue. Most areas in developing countries are sparsely populated and highly rural. Satellite communication is an excellent option for meeting this and many other pressing communication needs of developing economies. This paper examines the impact of satellite communication on developing economies, using popular examples as case study

    Architectures and Key Technical Challenges for 5G Systems Incorporating Satellites

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    Satellite Communication systems are a promising solution to extend and complement terrestrial networks in unserved or under-served areas. This aspect is reflected by recent commercial and standardisation endeavours. In particular, 3GPP recently initiated a Study Item for New Radio-based, i.e., 5G, Non-Terrestrial Networks aimed at deploying satellite systems either as a stand-alone solution or as an integration to terrestrial networks in mobile broadband and machine-type communication scenarios. However, typical satellite channel impairments, as large path losses, delays, and Doppler shifts, pose severe challenges to the realisation of a satellite-based NR network. In this paper, based on the architecture options currently being discussed in the standardisation fora, we discuss and assess the impact of the satellite channel characteristics on the physical and Medium Access Control layers, both in terms of transmitted waveforms and procedures for enhanced Mobile BroadBand (eMBB) and NarrowBand-Internet of Things (NB-IoT) applications. The proposed analysis shows that the main technical challenges are related to the PHY/MAC procedures, in particular Random Access (RA), Timing Advance (TA), and Hybrid Automatic Repeat reQuest (HARQ) and, depending on the considered service and architecture, different solutions are proposed.Comment: Submitted to Transactions on Vehicular Technologies, April 201

    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

    A Survey on Communication Networks for Electric System Automation

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    Published in Computer Networks 50 (2006) 877–897, an Elsevier journal. The definitive version of this publication is available from Science Direct. Digital Object Identifier:10.1016/j.comnet.2006.01.005In today’s competitive electric utility marketplace, reliable and real-time information become the key factor for reliable delivery of power to the end-users, profitability of the electric utility and customer satisfaction. The operational and commercial demands of electric utilities require a high-performance data communication network that supports both existing functionalities and future operational requirements. In this respect, since such a communication network constitutes the core of the electric system automation applications, the design of a cost-effective and reliable network architecture is crucial. In this paper, the opportunities and challenges of a hybrid network architecture are discussed for electric system automation. More specifically, Internet based Virtual Private Networks, power line communications, satellite communications and wireless communications (wireless sensor networks, WiMAX and wireless mesh networks) are described in detail. The motivation of this paper is to provide a better understanding of the hybrid network architecture that can provide heterogeneous electric system automation application requirements. In this regard, our aim is to present a structured framework for electric utilities who plan to utilize new communication technologies for automation and hence, to make the decision making process more effective and direct.This work was supported by NEETRAC under Project #04-157

    Will 5G See its Blind Side? Evolving 5G for Universal Internet Access

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    Internet has shown itself to be a catalyst for economic growth and social equity but its potency is thwarted by the fact that the Internet is off limits for the vast majority of human beings. Mobile phones---the fastest growing technology in the world that now reaches around 80\% of humanity---can enable universal Internet access if it can resolve coverage problems that have historically plagued previous cellular architectures (2G, 3G, and 4G). These conventional architectures have not been able to sustain universal service provisioning since these architectures depend on having enough users per cell for their economic viability and thus are not well suited to rural areas (which are by definition sparsely populated). The new generation of mobile cellular technology (5G), currently in a formative phase and expected to be finalized around 2020, is aimed at orders of magnitude performance enhancement. 5G offers a clean slate to network designers and can be molded into an architecture also amenable to universal Internet provisioning. Keeping in mind the great social benefits of democratizing Internet and connectivity, we believe that the time is ripe for emphasizing universal Internet provisioning as an important goal on the 5G research agenda. In this paper, we investigate the opportunities and challenges in utilizing 5G for global access to the Internet for all (GAIA). We have also identified the major technical issues involved in a 5G-based GAIA solution and have set up a future research agenda by defining open research problems

    Study of the benefits and applications of LEO for communications and definition of space new business models: project Kuiper - Amazon

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    El Project Kuiper és la nova constel·lació de satèl·lits que serà desplegada per Amazon durant els propers anys i que estarà emplaçada a LEO amb l'objectiu principal de proporcionar connectivitat de banda ampla, d'alta velocitat i de baixa latència a les comunitats no ateses o mal ateses de totes les parts del món. Aquest projecte té com a objectius, primerament, estudiar aquesta nova constel·lació per tal de conèixer els beneficis que li aportarà la seva baixa òrbita terrestre i després, desenvolupar el seu model de negoci a través del Model de Negoci CANVAS per extreure els seus factos clau d'èxit. A més a més, també s'han estudiat les noves oportunitats de negoci que sorgiran gràcies al desplegament de constel·lacions d'aquestes característiques.Project Kuiper is the new constellation of satellites to be deployed by Amazon over the next few years and placed in LEO with the primary goal of providing high-speed, low-latency broadband connectivity to unserved and underserved communities around the world. This project aims firstly to study this new constellation in order to know the benefits that its low terrestrial orbit will bring and then to develop its business model through the Business Model CANVAS to extract its key success factors. In addition, the new business opportunities that will emerge from the deployment of constellations of these characteristics have also been studied

    Prospects of 5G Satellite Networks Development

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    In the future, 5G networks will represent the global telecommunication infrastructure of the digital economy, which should cover the whole world including inaccessible areas not covered by 5G terrestrial networks. Given this, the satellite segment of 5G networks becomes one of the pressing issues of development and standardization at the second stage of 5G networks development in the period 2020–2025. The requirements for 5G satellite network will be determined primarily by combination of key services supported by 5G networks, which are combined by three basic business models of 5G terrestrial networks: enhanced Mobile Broadband Access (eMBB), Massive Internet of Things connections (mIoT), and Ultra-reliable low-latency communication (uRLLC). 3GPP as leading international standards body has identified several use cases and scenarios of 5G satellite networks development. 5G satellite networks are understood to mean networks in which the NG-RAN radio access network is constructed using a satellite network technology. The chapter has discussed the spectral and technological aspects of 5G satellite network developments, issues of architecture and role of delays on quality of services of 5G satellite segment, and possibility of constructing a 5G satellite segment based on distributed and centralized gNB base stations. The issues of satellite payload utilization have considered for bent-pipe and on-board processing technologies in 5G satellite segment
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