共查询到20条相似文献,搜索用时 31 毫秒
1.
Ricardo Castellot Lou Antonio Javier Sánchez Esguevillas Borja de la Cuesta Diego Belén Carro Linghang Fan Zhili Sun 《International Journal of Satellite Communications and Networking》2008,26(1):45-56
Satellite plays an important role in global information infrastructure (GII) and next generation networks (NGNs). Similarly, satellite communication systems have great advantages to support IPv6 (Internet Protocol version 6) networks as a technology that allows universal access to broadband e‐services (audio, video, VPN, etc.). In the context of DVB‐S2 (digital video broadcast‐satellite) and DVB‐RCS (digital video broadcast‐return channel via satellite) standards, this paper presents the current SatSix project (satellite‐based communications systems within IPv6 networks) within the European 6th Framework Programme, which is implementing innovative concepts and effective solutions (in relation with the economical cost) for broadband satellite systems and services using the technology presented above. This project is promoting the introduction of the IPv6 protocol into satellite‐based communication systems. Moreover, through SatSix, the industry is addressing the next generation Internet, IPv6. It also enhances its competitive position in satellite broadband multimedia systems by exploiting the common components defined by the European DVB‐S2 and DVB‐RCS satellite broadband standards. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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Tarik Taleb Abbas Jamalipour Nei Kato Yoshiaki Nemoto 《International Journal of Satellite Communications and Networking》2006,24(3):215-227
To meet an ever‐growing demand for wideband multimedia services and electronic connectivity across the world, development of ubiquitous broadband multimedia systems is gaining a tremendous interest at both commercial and academic levels. Satellite networks will play an indispensable role in the deployment of such systems. A significant number of satellite communication constellations have been thus proposed using Geostationary (GEO), Medium Earth Orbit (MEO), or Low Earth Orbit (LEO) satellites. These constellations, however, either require a potential number of satellites or are unable to provide data transmission with high elevation angles. This paper proposes a new satellite constellation composed of Quasi‐GeoStationary Orbit (Quasi‐GSO) satellites. The main advantage of the constellation is in its ability to provide global coverage with a significantly small number of satellites while, at the same time, maintaining high elevation angles. Based on a combination of this Quasi‐GSO satellites constellation and terrestrial networks, the paper proposes also an architecture for building a global, large‐scale, and efficient Video‐on‐Demand (VoD) system. The entire architecture is referred to as a ‘Theatre in the Sky’. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
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本文先说明卫星通信值得重视的优点。然后分别简述卫星ATM网、卫星多媒体系统和星上处理与交换 ,旨在介绍卫星通信正向宽带发展的趋势。 相似文献
4.
Jamalipour A. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》2001,89(1):88-104
Next-generation broadband satellite networks are being developed to carry bursty Internet and multimedia traffic in addition to the traditional circuit-switched traffic (mainly voice) on a global basis. These satellites provide direct network access for personal applications as well as interconnectivity to the terrestrial remote network segments. The main requirement in success of these networks is that they should be able to transmit high data rate traffic with prescribed quality of service (QoS). Thus, the broadband satellite network has no choice other than the rise of ATM technology and to be optimized for Internet-based traffic. ATM is the promising technology for supporting high-speed data transfer potentially suitable for all varieties of private and public telecommunications networks. IP, on the other hand is the fast-growing Internet layer protocol that is applicable over any data link layer Internet-based applications are the emerging source of traffic in the future wireless networks and broadband satellite networks should consider Internet as the primary service. In this paper, we discuss the traditional ATM and wireless ATM networks and explain the characteristics of the wireless IP networks. The paper then uses those concepts in defining the criteria for the broadband satellite networks such as the QoS and traffic management. Application of the broadband satellite networks is also proposed 相似文献
5.
阐述对同步卫星通信网发展方向提出的一些新要求:改进卫星ATM 宽带网结构和星上装置ATM 交换机,有效承担Internet 业务和采用按需提供带宽方式,提供数字电视广播和电视会议的应用 相似文献
6.
随着卫星网络以及通信系统的逐渐研发,宽带多媒体通信卫星系统在通信领域中备受关注.宽带多媒体通信卫星系统能够实现全球无缝隙覆盖的网络互连,在通信系统研发中发挥着重要的作用.基于宽带多媒体通信卫星系统运行维护管理是保障通信卫星系统稳定运行的基础.在本文中对基于ATM的宽带多媒体通信卫星系统运维管理技术进行研究. 相似文献
7.
Yunhui Zhou Fuchun Sun Bo Zhang 《International Journal of Satellite Communications and Networking》2007,25(6):603-617
The rapid advance of communication and satellite technology pushes broadband satellite networks to carry on multimedia traffic. However, the function of onboard routing cannot be provided in existing satellite networks with inter‐satellite links, and quality of service (QoS) of satellite networks cannot be reliably guaranteed because of great difficulties in processing of long distance‐dependent traffic. In this paper, a two‐layered low‐Earth orbit and medium‐Earth orbit satellite network (LMSN) is presented. A novel hierarchical and distributed QoS routing protocol (HDRP) is investigated, and an adaptive bandwidth‐constrained minimum‐delay path algorithm is developed to calculate routing tables efficiently using the QoS metric information composed of delays and bandwidth. The performance of LMSN and HDRP is also evaluated through simulations and theoretical analysis. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
8.
Alessandro Guidotti Alessandro Vanelli‐Coralli Tommaso Foggi Giulio Colavolpe Mrius Caus Joan Bas Stefano Cioni Andrea Modenini 《International Journal of Satellite Communications and Networking》2019,37(4):316-330
The integration of satellite and terrestrial networks is a promising solution for extending broadband coverage to areas not connected to a terrestrial infrastructure, as also demonstrated by recent commercial and standardisation endeavours. However, the large delays and Doppler shifts over the satellite channel pose severe technical challenges to traditional terrestrial systems, as long‐term evolution (LTE) or 5G. In this paper, 2 architectures are proposed for a low Earth orbit mega‐constellation realising a satellite‐enabled LTE system, in which the on‐ground LTE entity is either an eNB (Sat‐eNB) or a relay node (Sat‐RN). The impact of satellite channel impairments as large delays and Doppler shifts on LTE PHY/MAC procedures is discussed and assessed. The proposed analysis shows that, while carrier spacings, random access and RN attach procedures do not pose specific issues and hybrid automatic repeat request requires substantial modifications. Moreover, advanced handover procedures will be also required due to the satellites' movement. 相似文献
9.
Güray Aar Catherine Rosenberg 《International Journal of Satellite Communications and Networking》2005,23(4):229-245
Advanced resource management schemes are required for broadband multimedia satellite networks to provide efficient and fair resource allocation while delivering guaranteed quality of service (QoS) to a potentially very large number of users. Such resource management schemes must provide well‐defined service segregation to the different traffic flows of the satellite network, and they must be integrated with some connection admission control (CAC) process at least for the flows requiring QoS guarantees. Weighted fair bandwidth‐on‐demand (WFBoD) is a resource management process for broadband multimedia geostationary (GEO) satellite systems that provides fair and efficient resource allocation coupled with a well‐defined MAC‐level QoS framework (compatible with ATM and IP QoS frameworks) and a multi‐level service segregation to a large number of users with diverse characteristics. WFBoD is also integrated with the CAC process. In this paper, we analyse via extensive simulations the WFBoD process in a bent‐pipe satellite network. Our results show that WFBoD can be used to provide guaranteed QoS for both non‐real‐time and real‐time variable bit rate (VBR) flows. Our results also show how to choose the main parameters of the WFBoD process depending on the system parameters and on the traffic characteristics of the flows. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
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利用宽带卫星链路接入互联网是今后卫星通信的重要发展方向。首先介绍了基于宽带地球同步轨道(GEO,Geostationary Earth Orbit)网络移动的概念并以IPSTAR卫星为例建立模型,重点分析了基于宽带卫星移动通信的网络移动中的传输控制协议(TCP,Transfer Control Protocol)的特点,对TCP协议性能进行仿真模拟,最后分析了TCP协议在网络移动通信中的性能。结果证明,在宽带多媒体卫星移动通信中,由于系统允许信息传输具有较大带宽(IPSTAR中可以达到2 Mb/s),TCP传输的吞吐量和时延表现的较为稳定,因此,在基于宽带多媒体卫星的网络移动通信中实现TCP数据的传输具有一定的可行性。 相似文献
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The next generation of broadband satellite networks is challenged to accommodate multimedia services while concurrently integrating with terrestrial IP networks. With IP applications dominating the Internet, carrying IP traffic over the satellite has been under intensive study. Originally developed to bring digital television home through satellites, the DVB-S and DVB-RCS standards empower interactive satellite communications with economical standardized satellite terminals. Furthermore, onboard switching technology is increasingly gaining attention, due to optimized bandwidth usage, fully meshed network topology through one satellite hop, and quality of service guarantee. This article investigates the onboard switching technologies in DVB-S/DVB-RCS broadband satellite networks. Aside from the network system infrastructure and switch hardware architecture, the QoS mechanisms supported by the switch onboard the satellite are discussed in depth. 相似文献
14.
In‐line interference mitigation techniques for spectral coexistence of GEO and NGEO satellites
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Shree Krishna Sharma Symeon Chatzinotas Björn Ottersten 《International Journal of Satellite Communications and Networking》2016,34(1):11-39
The interest towards the deployment of Low Earth Orbit (LEO)/Medium Earth Orbit (MEO) satellite systems in several frequency bands is increasing due to the requirement of low latency for real‐time systems and high demand of broadband data. When the number of usable Non‐Geostationary (NGEO) satellites, that is, LEO/MEO in space, increases, the frequency coexistence between the NGEO satellite systems with the already existing geostationary (GEO) satellite networks becomes a requisite. In this context, it is crucial to explore interference mitigation techniques between GEO and NGEO systems in order to allow their spectral coexistence. More specifically, in the coexistence scenario of GEO and NGEO satellite networks, in‐line interference may be a serious problem, especially in the equatorial region. In this paper, we provide several frequency sharing studies in the context of the coexistence of an NGEO satellite link with another NGEO/GEO satellite link. Furthermore, we carry out interference analysis between GEO and MEO satellite systems considering the case of the O3b satellite system and propose an adaptive power control technique for both the uplink and downlink scenarios in order to mitigate the in‐line interference. Moreover, we suggest several cognitive solutions for mitigating the in‐line interference and provide future research issues. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
15.
探讨了异构计算环境下的实时多媒体通信以及ATM(异步传输模式)网络上能提供服务保证的高性能宽带多媒体应用,设计了异构环境下基于Native-ATM(纯ATM)方式的实时多媒体通信系统,该系统在两不同的计算机系统之间实现了基于ATM AAL5协议的实时多媒体通信数据流的互通,为异构环境下宽带分布多媒体应用的研究创造了良好的基础。 相似文献
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Richard S. Weil 《Alternatives to the High Cost of Litigation》2014,32(9):138-139
Remember how we resolved disputes as kids? No, not the way that resulted in bloody noses. The more peaceful way, like –
- Ro‐sham‐bo (Rock Paper Scissors)
- Eeny‐meeny‐miny‐mo
- Flipping a coin
- Guess which hand the rock is in
- Choosing sides or first‐ups by tossing a baseball bat
- Drawing straws
- One potato, two potato
- Odds and evens
- Arm wrestling
18.
Asynchronous transfer mode (ATM) has emerged as a possible contender for the next generation switching system and fundamental transport basis for the broadband integrated services digital network (B-ISDN) and telecommunications in the future. It is widely thought of as the network to accommodate the uncertain requirements of future public communications because of its high degree of flexibility and service independency. The Orwell protocol developed by British Telecom can provide a communication base to meet the requirements of such a network. Orwell is used as a slotted ring protocol designed to carry a mixture of services which form the basis of an ATM network. The authors describe the realisation of a 155.52 Mbit/s fibre-optic physical layer from the Orwell protocol based on an ATM technology, and also discuss how the Orwell protocol can offer broadband transport capabilities and can provide access to and interwork with existing networks, such as telephone networks and 64 kbit/s based ISDNs 相似文献
19.
Erhan Ekmekcioglu Barry Evans Ahmet Kondoz Paul Thompson Luc Ottavj Fabrice Gamberini Simon Watts 《International Journal of Satellite Communications and Networking》2019,37(6):513-526
One of the key performance targets on the European Commission's Digital Agenda is to provide at least 30‐Mbit/s broadband coverage to all European households by 2020. The deployment of existing terrestrial technologies will not be able to satisfy the requirements in the most difficult‐to‐serve locations, either due to a lack of coverage in areas where the revenue potential for terrestrial service providers is too low or due to technological limitations that diminish the available throughput in rural environments. In this paper, we investigate a hybrid broadband system combining satellite and terrestrial access networks. The system design and the key building blocks of the intelligent routing entities (referred to as intelligent gateways) are presented. To justify the hybrid broadband system's performance subjectively, lab trials have been performed with an integrated multiple access network emulator and a variety of typical multimedia applications that have varying requirements. The results of the lab trials suggest that the quality of experience is consistently improved thanks to the utilisation of intelligent gateway devices, when compared with using a single access network at a time. 相似文献
20.
卫星ATM交换系统的连接允许控制算法研究 总被引:4,自引:1,他引:3
连接允许控制(Connection Admission Control,CAC)是卫星ATM交换系统中很重要的部分。从带宽利用率和计算复杂度的角度对当前几种比较流行的CAC算法进行了分析、比较和仿真,并结合卫星通信的特点,从中挑选出一种适合卫星ATM交换系统的CAC算法。 相似文献