20 research outputs found
An enhanced TCP congestion avoidance scheme and its performance evaluation in high speed satellite networks
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
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
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
NGSO Constellation Design for Global Connectivity
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
TRANSPORT PROTOCOL AND FLOW CONTROL FOR IP-BASED BROADBAND AERONAUTICAL SATELLITE NETWORKS
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