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.     

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。     

甚小天线地球站在云南的应用

本文详细介绍了云南省甚小天线地球站的应用情况和扩容计划，并根据近一年的应用实践，提出了的问题和现有系统无法克服的弱点，指出今后应以可承载综合业务的Ｋｕ频段卫星通信为发展方向。     

国外典型的VSAT用户网络

ＶＳＡＴ是８０年代中期迅速发展起来的新型卫星通信技术，具有投资少、见效快、周期短、应用广泛等特点。本文着重介绍国外一些典型的ＶＳＡＴ用户网络的情况。     

VSAT networks in India—specifications and applications

This paper describes briefly the evolution of VSATs in India, including the existing and proposed networks and their applications. The salient specifications of the various types of VSATs are described. Some of the VSATs under advanced stages of development as well as those to be used in proposed networks due for implementation soon are also covered.     

印度利用VSAT建立空中信息高速公路

ＶＳＡＴ卫星通信网能为那些经济角度来看不适合建立微波通信或光纤通信。但确需通信的地区提供通信服务。印度政府经过了认真论证，根据本国国情从９０年代初开始引入ＶＳＡＴ技术，建立了多个ＶＳＡＴ网络，并且利用ＶＳＡＴ卫星通信网建设印度特色的“空中信息高速公路”以满足其国内对高速通信的要求。     

卫星互联网下的VSAT卫星通信

本文介绍了VSAT通信在卫星互联网下的新发展,分析了VSAT系统的互联网接入方式,研究了卫星互联网的技术热点,展望了卫星互联网的发展前景.     

VSAT卫星通信网及其发展趋势

本文介绍VSAT卫星通信网的组成、特点和各种多址方式,预测其技术发展趋势。     

小型卫星地面站中ODU控制器的通信模块设计

文章主要介绍了小型卫星地面站(VSAT，Very Small Aperture Terminal)中的室外单元(ODU，Outdoor Unit)控制器的通信模块设计。VSAT是控制卫星通信的设备之一，由室外单元ODU和室内单元IDU(Indoor Unit)两部分组成。传统VSAT中控制ODU的方法是通过BUC与PC机连接，对ODU进行操纵。而现在可以利用该控制器体积小、功能强的特点，将它和BUC捆绑起来使用，为用户提供了很大的便利。     

VSAT通信在海洋船舶上的应用研究

VSAT(Very Small Aperture Terminal)即"甚小孔径终端",它是一种微型的卫星通信地球站,是上世纪80年代所研发的卫星通信系统.该系统设备的天线口径极小(0.3~1.4m),且设备结构相当紧凑,拥有固体、智能化属性,在应用环境方面受制范围小,组网相当灵活,所以它在当前的海洋船舶通信方面起着巨大的应用价值.通过研究由它所构成的海洋船舶卫星通信网络及系统,分析VSAT系统链路程序,构建船载VSAT寻星系统将成为本文研究的主要内容.     

宽带VSAT网络中的多址技术

多址技术是宽带VSAT网络中的关键技术，先分析讨论了目前宽带卫星网络中提出的多种多址技术，业务使用的多址方式．它对用户的QoS要求和卫星信道的利用率都有重要的影响．文中首指出它们各自在应用中可能存在的问题：然后具体分析了ATM各类     

浅析VSAT通信在远程视频监控系统中的应用

VSAT通信用于远程视频监控系统具有一定的优势,它主要使用C波段和Ku波段,既能用于固定远程视频监控又能用于移动远程视频监控,而星状网是首选的网络结构。     

A canadian perspective on vsats: Regulatory,technical and operational methodologies

VSAT systems have undergone a spurt of growth in recent years in Canada, particularly at K_u band using the star topology. This paper describes the regulatory, technical and networking issues in Canada. It starts out by describing the regulatory framework which has evolved in Canada to promote and foster the development and growth of such systems. It then provides a technical overview of the existing systems and possible evolution paths towards further enhanced capabilities. These include mesh networking and ISDN compatibility/capability. Finally, it discusses some end-to-end VSAT networking issues, including the interconnection of VSAT systems with the public switched network.     

Satellite broadcasting: System concepts and the television transmission standards for europe

Within Western Europe several countries have indicated their intention to start DBS services in the 12 GHz band in 1985/6 or soon after. Against this background the European Broadcasting Union has recommended a common transmission standard known as C-MAC/packet. An outline is given of the system, with a discussion of the requirements for a broadcasting satellite and receivers for individual reception.     

VSAT通信系统及其在远程教育中的应用

20世纪80年代,VSAT通信系统就在我国有了发展,在金融证券、海关贸易、气象观测预报以及一些其他大型企业的通信中得到了广泛的应用。介绍了VSAT通信系统的特点、构成、网络结构及其在远程教育中的教学方式,并就运用VSAT通信系统开展远程教育中需要考虑的因素谈了自己的观点和建议。     

VSAT networks in the intelsat system

This paper describes how VSAT networks currently operate in the INTELSAT system. Four classes of VSAT networks (data transaction; circuit-switched; data distribution; microterminals) are identified, and it is verified that all of them can operate with INTELSAT satellites. Most VSAT networks in operation on INTELSAT today operate in fractional transponder leases. Fractional transponder capacity estimates are presented for a wide range of scenarios and different INTELSAT satellite series. These estimates clearly show increasing bandwidth utilization efficiencies for newer generations of INTELSAT satellites. Provided that VSAT and hub sizes are appropriately selected, efficiencies are already significant with existing satellites. Two possible ways of increasing the utilization of satellite resources are examined in the paper: demand assignment multiple access (DAMA) and multiple channel-per-carrier (MCPC) techniques. The impact of using DAMA in circuit-switched VSAT networks is quantified.     

Standardization of VSAT communication systems in the CCIR

This paper presents an overview of the CCIR Recommendations on VSAT systems. The first part presents the activities of the CCIR Task Group 4/2 which was created in 1990 and issued five Recommendations for VSAT earth-stations. These Recommendations specify the RF characteristics of the VSAT earth-stations and their maintenance functions. The TG 4/2 finished its task in 1991. The second part of this paper presents the activities of the CCIR Task Group 4/3 which was created in 1991 for the preparation of Recommendations on the connection of VSAT networks with the public switched networks. The activities of the TG 4/3 are still going on, and the Draft Recommendations will be formalized in two more meetings. The subjects of dicussion and the expected outcomes will be briefly presented.     

基于多线程的VSAT卫星通信系统的网控中心的设计与实现

网控中心（ＮｅｔｗｏｒｋＣｏｎｔｒｏｌＣｅｎｔｅｒ）是ＶＳＡＴ卫星通信系统的核心。本文讨论网控中心的设计与实现。论文首先简要介绍了一种容错的网控中心结构模型，该模型采用的主要策略是冗余备份。然后，进一步讨论了网控中心的可靠性设计。最后，介绍了一种基于多线程的网控中心的实现。通过利用多线程和多级容错措施等方法，我们实现的网控中心具有可靠性好，高性能，容易使用等特点。     

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。     

利用VSAT网实现局域网与Internet互连

Internet在全世界已日益发展和普及。文章简要介绍了利用VSAT网实现局域网（LAN）与Internet互连的特点与方法，为用户尤其是边远地区用户接入Internet提供了一种新的可行的途径。