18,332 research outputs found

    Towards generic satellite payloads: software radio

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    Satellite payloads are becoming much more complex with the evolution towards multimedia applications. Moreover satellite lifetime increases while standard and services evolve faster, necessitating a hardware platform that can evolves for not developing new systems on each change. The same problem occurs in terrestrial systems like mobile networks and a foreseen solution is the software defined radio technology. In this paper we describe a way of introducing this concept at satellite level to offer to operators the required flexibility in the system. The digital functions enabling this technology, the hardware components implementing the functions and the reconfiguration processes are detailed. We show that elements of the software radio for satellites exist and that this concept is feasible

    SDN/NFV-enabled satellite communications networks: opportunities, scenarios and challenges

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    In the context of next generation 5G networks, the satellite industry is clearly committed to revisit and revamp the role of satellite communications. As major drivers in the evolution of (terrestrial) fixed and mobile networks, Software Defined Networking (SDN) and Network Function Virtualisation (NFV) technologies are also being positioned as central technology enablers towards improved and more flexible integration of satellite and terrestrial segments, providing satellite network further service innovation and business agility by advanced network resources management techniques. Through the analysis of scenarios and use cases, this paper provides a description of the benefits that SDN/NFV technologies can bring into satellite communications towards 5G. Three scenarios are presented and analysed to delineate different potential improvement areas pursued through the introduction of SDN/NFV technologies in the satellite ground segment domain. Within each scenario, a number of use cases are developed to gain further insight into specific capabilities and to identify the technical challenges stemming from them.Peer ReviewedPostprint (author's final draft

    Reliable multicast transport by satellite: a hybrid satellite/terrestrial solution with erasure codes

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    Geostationary satellites are an efficient way to provide a large scale multipoint communication service. In the context of reliable multicast communications, a new hybrid satellite/terrestrial approach is proposed. It aims at reducing the overall communication cost using satellite broadcasting only when enough receivers are present, and terrestrial transmissions otherwise. This approach has been statistically evaluated for a particular cost function and seems interesting. Then since the hybrid approach relies on Forward Error Correction, several practical aspects of MDS codes and LDPC codes are investigated in order to select a code

    Multicast Mobility in Mobile IP Version 6 (MIPv6) : Problem Statement and Brief Survey

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    Design issues for the Generic Stream Encapsulation (GSE) of IP datagrams over DVB-S2

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    The DVB-S2 standard has brought an unprecedented degree of novelty and flexibility in the way IP datagrams or other network level packets can be transmitted over DVB satellite links, with the introduction of an IP-friendly link layer - he continuous Generic Streams - and the adaptive combination of advanced error coding, modulation and spectrum management techniques. Recently approved by the DVB, the Generic Stream Encapsulation (GSE) used for carrying IP datagrams over DVBS2 implements solutions stemmed from a design rationale quite different from the one behind IP encapsulation schemes over its predecessor DVB-S. This paper highlights GSE's original design choices under the perspective of DVB-S2's innovative features and possibilities

    The Beginnings and Prospective Ending of “End-to-End”: An Evolutionary Perspective On the Internet’s Architecture

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    The technology of “the Internet” is not static. Although its “end-to- end” architecture has made this “connection-less” communications system readily “extensible,” and highly encouraging to innovation both in hardware and software applications, there are strong pressures for engineering changes. Some of these are wanted to support novel transport services (e.g. voice telephony, real-time video); others would address drawbacks that appeared with opening of the Internet to public and commercial traffic - e.g., the difficulties of blocking delivery of offensive content, suppressing malicious actions (e.g. “denial of service” attacks), pricing bandwidth usage to reduce congestion. The expected gains from making “improvements” in the core of the network should be weighed against the loss of the social and economic benefits that derive from the “end-to-end” architectural design. Even where technological “fixes” can be placed at the networks’ edges, the option remains to search for alternative, institutional mechanisms of governing conduct in cyberspace.
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