浅析VSAT通信在海洋船舶上的应用

随着海洋上活动的增加,海洋上的通信需求越来越高,VSAT通信作为一种通信手段,由于其具有一定的优势,正在海洋船舶上逐渐得到使用.随着VSAT通信在海洋上的使用,诸如远程监控、视频会议、Internet等在海洋船舶上得到应用.由于VSAT通信的特点,星状网络是首选网络结构,C波段和Ku波段是2种主要的卫星通信波段.     

船载VSAT动中通天线测试技术指标研究

本文以保障船舶VSAT小站通信链路的稳定性为根本要求,以VSAT网络运营者的角度,从保障通信链路的稳定建立方面,介绍了对船载卫星通信天线的指标要求及测试技术指标,阐明了在工程技术应用上,船载动中通天线的测试技术指标,以确定船舶卫星通信天线系统的选择,保障卫星通信的链路稳定可靠性,提升运营服务水平。     

“863”通信技术跟踪报告之三 卫星互联网技术

一、VSAT的发展由于Internet的驱动,像其他通信技术一样,卫星通信正转向满足数据通信的全面需求。具体地讲,一方面已经成熟的基于C波段和Ku波段技术的VSAT系统不断演进满足了Internet业务的要求,并成为全球Internet网的一个重要组成部分,另一方面采用更高的Ka频段技术、可真正实现个人通信的宽带卫星通信系统,特别是低轨道卫星群系统正在开发、试验和建设之中,卫星通信被越来越多的电信网运营者、ISP及ICP等选作提供Internet服务的重要手段。目前,VSAT是卫星通信中的主流技术,它的应用相当成功和普及,但传统VSAT提供…     

VSAT系统

卫星通信是现代通信技术的一个重要方面。一般的卫星通信地球站设备庞大，使用条件要求高，限制了它的应用范围。而甚小天线卫星通信地球站（VSAT）的天线直径不超过3米，设备结构紧凑，智能化，价格便宜，安装维护也方便，组网灵活，因此得到广泛的应用，发展很快。本文以日本NEC公司的NEXTAR系统为例，为我们描绘出VSAT系统的概貌。     

VSAT卫星通信网络系统的研究分析

甚小天线地面站(Very Small Aperture Terminal,VSAT)实际上指的是直接安装在使用地点并可直接联接用户设备的小型卫星通信地球站,其本身在应急通信保障系统领域中占有领军地位。本文阐述我国VSAT通信业务系统的发展,VSAT通信系统的组成,VSAT的分类,以及VSAT通信系统的特征。     

VSAT卫星通信系统及应用

文章概括了我国通信业务发展的四个阶段,在此基础上分析了甚小型口径天线终端(VSAT)卫星通信系统在技术上的特点和优势。结合云南烟草全国卫星通信专用网的应用实例,介绍了该VSAT卫星通信专用网的网络组成与结构,分析了该网络中电话通信网和数据通信网的工作过程,以及该专用网对地球站设备的基本要求。VSAT卫星通信业务以其特有的优势,在现有应用的基础上还将在实施快速救援、处理等应急指挥等方面大有作为。     

VSAT卫星通信技术的发展与应用

本文从VSAT卫星通信系统的参数、特点、优点、网络构成及连接方式。VSAT通信网的通信规程协议。VSAT通信网的网络管理，VSAT卫星通信的发展趋势。VSAT卫星通信存在的问题，中国VSAT卫星通信未来的对策等方面。详细地介绍了VSAT通信技术的应用与发展。     

VSAT卫星通信系统及应用分析

VSAT自二十世纪六十年代发展至今,其卫星通信系统得到了广泛应用。目前VSAT卫星通信系统已经成为移动通信的核心部分之一,具有成本低、安装便捷和覆盖面广等优势。本文主要从VSAT卫星通信系统的概述入手,详细介绍了VSAT卫星通信系统的发展史,阐述了VSAT卫星通信系统的优势和具体应用,以充分发挥VSAT卫星通信系统的优势。     

VSAT建站中常遇到的几个问题

VSAT具有投资少，组网灵活、设备体积小安装容易等特点可以直接安装到用户，广泛应用于卫星寻呼金融系统证券业企业专网村通工程等领域，为之提供数据，语音，图像和多媒体综合业务；在卫星通信向灵活性小型化方向发展的今天，VSAT卫星通信系统具有广阔的应用前景。安装VSAT设备不是很难，但以下几个方面的问题经常被忽视，使安装过程不顺利。     

新型宽带卫生通信产品SurfBeam

网络宽带化进程的不断加快对卫星通信提出了前所未有的挑战,作为新一代宽带卫星通信产品 SurfBeam,以其超前的设计理念和优越的性能,在国际卫星通信市场上占据了领先地位,本文就其技术优势、系统组成进行介绍,使读者能够对该系统有一个大致的了解甚小口径终端(VSAT)出现之初只是针对单一的话音、数据等窄带业务而设计,随着卫星宽带业务的不断发展,VSAT在原来基础上不断改进来适应宽带业务的需要,出现了一系列的宽带VSAT产品,但与地面宽带网络的发展相比仍然表现得力不从心作为在宽带IP卫星设备研发、生产和技术支持方面领先的国际制造商,美国卫讯公司rVjasal)将有线电视宽带接入标准(DOCSlS) (DataOver-Cable Se rvice Inte rfaceSpecificalion)和最新的卫星通信技术结合在一起,推出了新一代宽带卫星通信产品SurfBeam.     

基于DVB-RCS的VSAT宽带卫星通信技术与应用

介绍了VSAT数据网原理、卫星通信系统宽带化的发展趋势及DVB-RCS开放标准。通过介绍基于DVB-RCS的VSAT宽带卫星通信系统在工程中的应用实例,其中包括系统业务与特点,以及各子系统的基本配置等,可以得出,随着网络和业务的宽带化,VSAT卫星通信系统正在从传统的窄带向宽带系统转变。在现有技术中,基于DVB-RCS...     

VSAT卫星通信小站设备常见故障原因与解决

随着卫星通信技术的发展,VSAT卫星通信设备在气象部门正得到广泛的应用。本文针对VSAT卫星通信小站设备在通信中常见的故障进行了原因分析,并提出了具体的解决方法。     

VSAT卫星通信技术的应用分析

文中简要讲述了VSAT技术的发展历程，讨论了卫星通信系统的基本结构与连接形式。同时，文中重点探究了VSAT卫星通信的应用，从组网与波段、冗余设计、主站、附加功能等方面入手，探究了设计应用问题，并简述其了实际应用情况。     

DVB-RCS卫星互动网络的研究

DVB-RCS卫星互动网络,应用前景广阔。DVB-RCS标准是为了在单向的卫星广播网络中(DVB-S)实现双向互动网络而采纳的一系列技术规范,但标准中仅规定了空中接口,没有提到如何实现一个网络的MAC接入层。卫星网络的实现结构是其MAC接入层协议的重要组成部分。本文设计了一个DVB-RCS卫星互动网络的网络结构,重点解释了它的多址接入方式和资源分配方式,最后描述了它的入网过程。     

走向宽带化的VSAT卫星通信

受数据音频视频广播、计算机卫星宽带交互接入和音视频会议等业务的推动,VSAT卫星通信网向宽带业务发展巳成为必然趋势。分别对应以上业务的VSAT卫星通信网也日益趋于融合成一个统一的宽带VSAT通信网。发展宽带VSAT通信网的关键技术涉及到宽带数据广播、宽带多址接入、卫星通信规程、网络综合管理和宽带虚拟子网等。     

Guidelines for a preliminary dimensioning of a transaction-oriented vsat network

Very small aperture terminal (VSAT) satellite networks have recently emerged as an attractive and cost-effective alternative to traditional terrestrial circuit or packet switching networks for transaction enquiry-response data applications. VSAT star networks are particularly well adapted to this kind of application, offering high link reliability, better flexibility, wide service area coverage and several economic and operational advantages. However, one major drawback associated with satellite links is the relatively high propagation delay, which is about 0·27 s for one hop (ground–satellite-ground). This requires special design and dimensioning optimization in order to keep the response time of the network within acceptable limits. This paper provides guidelines for the dimensioning of such enquiry-response star VSAT networks. Dimensioning refers to determining the minimum transmission bit rates required, on the different terrestrial and satellite segments of the network, for a given network configuration and mean delay requirement. The approach presented in this paper allows network designers to determine, in a simple way, the required modem speeds of the network segments.     

VSAT communications networks-an overview

The very-small-aperture-terminal (VSAT) fixed satellite communication network is a star network in which many dispersed micro terminals attempt to send data in a packet form through a random access/time-division multiple-access (RA/TDMA) satellite channel with transmission delay. The basic concept of the VSAT and its service potential are discussed. Two classes of traffic are addressed, namely business-oriented low-rate-data traffic and bulk data traffic of corporate networks. Satellite access, throughput, and delay are considered. The size of the network population that can be served in an RA/TDMA environment is calculated. User protocols are examined. A typical VSAT business scenario is described     

基于卫星数据通信网络ISBN的视频／音频多路广播

介绍ＩＰ多路广播技术在广域网中的应用，通过描述ＴＣＰ／ＩＰ协议中ＩＰ多路广播的特点和基于卫星数据网的多路广播网络结构，结合多路广播应用软件在休斯综合卫星业务图ＩＳＢＮ上的实现，提供了一种充分利用卫星通信独有的覆盖面广的广播优势和经济有效的传播多媒体信息的技术手段。     

The development of VSAT performance standards in the United States of America

During the 1980s, when satellite communication systems and applications experienced significant growth, the Federal Communications Commission (FCC) in the U.S. recognized that special regulations were required for the licensing and operation of VSAT systems in order to maintain efficient use of the radio spectrum and geostationary orbit (GSO) and to expedite the authorization of VSAT networks featuring large numbers of earth-stations. The FSS allocated frequency bands, which are used extensively by domestic satellite communication systems in the U.S. and throughout Region 2, are in the 4–6 GHz and 12–14 GHz bands. In order to satisfy the heavy demand in the U.S. for fixed satellite services in these bands, the FCC devised an orbit plan of two degrees spacing between satellites in the relevant portion of the GSO. In a co-coverage environment, the two most important technical factors for controlling interference between neighbouring satellite systems are (1) earth-station antenna discrimination and (2) cross-polarization. Since VSAT systems, by definition, use very small aperture terminals with relatively low levels of antenna discrimination, it was necessary to establish limits for transmit power flux densities and the minimum size of antennas. These limits, based on compatible operation at two-degree satellite orbit separations, evolved into VSAT standards for the U.S. domestic satellite industry. To expedite the licensing of large numbers of VSAT terminals, conforming systems were given ‘blanket authorizations’ for all VSATs in a network. This paper traces the history of the development of VSAT standards in the U.S. and discusses the technical considerations which were used in these developments. A brief review of receive-only (RO) terminals is also provided.     

VSAT networking concepts and new applications development

The authors present some innovative very small aperture terminal (VSAT) technology that can be used to support new applications. The first of these applications explores the possibility of realizing a VSAT-based satellite wide area network (SWAN) to provide flexible interconnection between local area networks (LANs) and metropolitan area networks (MANs) as well as gateway access to centralized information databases and computing services. A second application deals with the potential provision of ISDN-compatible services via VSATs in conjunction with existing satellites as well as future advanced satellites (ADSATs) having onboard switching and processing capabilities. The use of VSATs to solve backhaul interconnection/internetworking problems associated with evolving mobile satellite (MSAT) communication networks is discussed