20 research outputs found

    An enhanced TCP congestion avoidance scheme and its performance evaluation in high speed satellite networks

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    High speed satellite communication networks are emerging as part of the future global wireless communication systems. However, existing transmission control protocols for satellite networks do not provide satisfactory performance over high speed satellite links due to their inefficient congestion avoidance algorithms. This paper identifies the reason for low throughput of a widely used protocol Space Communications Protocol Specification (SCPS) in such networks and proposes a new Transmission Control Protocol (TCP) congestion avoidance algorithm to overcome the drawback of the congestion avoidance algorithm used in the SCPS protocol. Numerical results through simulations demonstrate that the proposed new algorithm can achieve significant throughput improvement over links with variable error rates, compared with its legacy counterpart

    TCP over Satellite Hybrid Networks: A Survey

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    Satellite is going to play an important role in the global information infrastructure. Satellite canprovide direct to home Internet service (i.e. DirecPC from Hughes Network System) and it can alsoserve as traffic trunk in the middle of the network. About 98 percent of the Internet traffic is TCPtraffic. TCP works well in the terrestrial fiber network. However, in the satellite hybrid networks,because of the long propagation delay, large bandwidth-delay product, high bit error rate anddownstream/upstream bandwidth asymmetry, TCP performance degrades dramatically. This paperaddresses the problems of TCP in satellite data networks and reviews the proposed solutions in theliterature. For each solution, the advantages and disadvantages are pointed out. In addition,extensive simulations have been done for the proxy based scheme currently used in the industry tofind out how and to what extent the enhancements, such as connection splitting, window scalingand selective acknowledgement, benefit the TCP throughput

    Flow Control at Satellite Gateways

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    Abstract-- Broadcast satellite networks are going play an important role in the global information infrastructure. Several systems including DirecWayfrom Hughes Network System use satellites to provide direct-to-user high speed Internet services. TCP works well in the terrestrial fiber networks but does not work well in satellite hybrid (satellite-terrestrial) networks. In this paper we analyze the problems that cause this dramatically degradedperformance. Based on the observation that it difficult for an end-to-end solution to solve these problems in this kind of hybrid networks, we propose a connection splitting based solution. A rate-based protocol is designed for the satellite connections and a flow control scheme at the satellite gateways (SGW) used to couple the two split connections together.Our simulation results shows that our scheme can maintain high utilization of the satellite link and improve fairness among the competing connections

    ADHOCTCP: Improving TCP Performance in Ad Hoc Networks

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    NGSO Constellation Design for Global Connectivity

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    Non-geostationary orbit (NGSO) satellite constellations represent a cornerstone in the NewSpace paradigm and thus have become one of the hottest topics for the industry, academia, but also for national space agencies and regulators. For instance, numerous companies worldwide, including Starlink, OneWeb, Kepler, SPUTNIX, and Amazon have started or will soon start to deploy their own NGSO constellations, which aim to provide either broadband or IoT services. One of the major drivers for such a high interest on NGSO constellations is that, with an appropriate design, they are capable of providing global coverage and connectivity.Comment: Book chapter submitted to IET Non-Geostationary Satellite Communications System

    Non- geostationary orbit constellation design for global connectivity

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    TRANSPORT PROTOCOL AND FLOW CONTROL FOR IP-BASED BROADBAND AERONAUTICAL SATELLITE NETWORKS

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    The IP-based broadband aeronautical satellite network will provide numerous new applications and services for both airspace system operations and passenger communications. However, the interoperation between a satellite system and the exiting terrestrial Internet infrastructure introduces new challenges. In this thesis, we recommend suitable transport protocols for an aeronautical network supporting Internet and data services via satellite. We study the future IP-based aeronautical satellite hybrid network and focus on the problems that cause dramatically degraded performance of the Transport Protocol. Based on the observation that it is difficult for an end-to-end TCP solution to solve the performance problem effectively, we proposed a new splitting based transport protocol, called Aeronautical Transport Control Protocol (AeroTCP). The main idea of AeroTCP is the fixed window flow control, adaptive congestion control, and super fast error control. Simulation results showed that AeroTCP can achieve high utilization of satellite channel and fairness
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