The USSR and satellite communications : Competition and cooperation

This article examines the USSR's satellite communications provision in the international arena. The author first outlines the Intercosmos programme, collaboration between the USSR and France and India, and maritime satellite communications. He then discusses in detail the INTERSPUTNIK system, and Soviet international coverage and competitiveness in television. In conclusion, the complex interaction and overlap between cooperation and competition in space is explained.     

Economics of satellite communications systems

This paper is partly a tutorial, telling systematically how one goes about calculating the total annual costs of a satellite communications system, and partly the expression of some original ideas on the choice of parameters so as to minimize these costs.The calculation of costs can be divided into two broad categories. The first is technical and is concerned with estimating what particular equipment will cost and what will be the annual expense to maintain and operate it. One starts in the estimation of any new system by listing the principal items of equipment, such as satellites, earth stations of various sizes and functions, telemetry and tracking equipment and terrestrial interfaces, and then estimating how much each item will cost. Methods are presented for generating such estimates, based on a knowledge of the gross parameters, such as antenna size, coverage area, transmitter power and information rate. These parameters determine the system performance and it is usually possible, knowing them, to estimate the costs of the equipment rather well. Some formulae based on regression analyses are presented. Methods are then given for estimating closely related expenses, such as maintenance and operation, and then an approximate method is developed for estimating terrestrial interconnection costs.It is pointed out that in specific cases when tariff and geographical information are available, it is usually better to work with specific data, but nonetheless it is often desirable, especially in global system estimating, to approximate these interconnect costs without recourse to individual tariffs. The procedure results in a set of costs for the purchase of equipment and its maintenance, and a schedule of payments. Some payments will be incurred during the manufacture of the satellite and before any systems operation, but many will not be incurred until the system is no longer in use, e.g. incentives. In any case, with the methods presented in the first section, one arrives at a schedule of costs and payments for all the items and the years in which they will be incurred. The second category of costing problems is one of financing or engineering economics. All the costs are first “present valued” to some reference period using rates of return appropriate to the particular situation.One finally arrives at sets of annual costs which can be used as the basis for setting lease costs or revenue requirements and tariffs. The correspondence between methods using discounted rates of return and capital recovery formulae on one hand and those using various depreciation schedules, such as is typical of regulated industries on the other hand, is discussed.The remainder of the paper is devoted to discussing the relationship between critical parameters, such as replacement schedules, design lifetime, satellite power and Earth station antenna size, and the overall costs.It is shown that optima for these parameters may exist and can be calculated. In particular, the optimization of satellite replacement schedules to minimize the present value of total investment over a very long period is presented, along with simplified versions of the theory suitable for system planning.The choice of EIRP is also discussed and a procedure for choosing the value that minimizes the costs is shown.     

High thermally conductive communications equipment panel module for communications satellite

A new communications equipment panel module for satellite use has been developed to obtain a high thermal conductivity across the thickness in transversal direction of the panel. As the conventional communications equipment panel has a sandwich structure with aluminum alloy face sheets and a honeycomb core, the transversal thermal conductivity is relatively small mainly due to epoxy resin adhesive layers between the face sheet and the honeycomb core. Therefore, in order to dissipate high-heat flux towards space, a complicated thermal control system becomes necessary. The new panel module consists of a carbon-fiber-reinforced aluminum-alloy face sheet and a titanium-alloy core. A metallic bonding is used as the connection between the face sheet and core to enhance thermal conductivity of the panel is 1 × 10⁻¹ (W/K · mm) which is approx. 1000 times larger than that of the conventional panel.     

Policy and regulatory risk considerations for satellite communications

The London Institute of Space Policy and Law is presenting a series of seminars on risks associated with space activity and its insurance, aimed at fostering better understanding of the risks particular to commercial space projects, and at encouraging appropriate policy measures. Seminar IV-I on 5 February 2010 focused on policy and regulatory risk considerations for satellite communications. After an introduction by the seminar chair Jeremy Rose, senior consultant at telecommunications consultancy Comsys, and a welcome from Institute Director Sa'id Mosteshar, four speakers outlined the ideal regulatory framework for satellite communications, as well as current regulatory and policy risks at the international, regional and national level. Risks were discussed in ITU, EU and UK procedures and policies and debate was continued from the floor. The event's rapporteur summarizes the issues highlighted by the speakers and some of the interventions from the floor.     

Advanced high capacity domestic satellite communications system

This paper describes a concept of multibeam high capacity transmission possible with a 30/20 GHz and 50/40 GHz domestic satellite communication system. The relationship between satellite antenna pointing accuracy and multi-beam antenna interference, as well as the relationship between satellite antenna pointing accuracy and multi-satellite interference are looked at.The ultra high capacity domestic satellite communication system will have multi-beam antennas with a 76.0 dB at both 20 GHz and 40 GHz. These antennas will provide 4950 beams that approximately correspond to the number of end office of the Japanese telephone network, and have a pointing accuracy of 0.005 degrees. This system will be equipped with 9900 30/20 GHz and 50/40 GHz transponder channels with bit rates of 800 Mbps. Its capacity will be 119 Tbps through use of 15 large communication satellite platforms.     

Will fiber optics threaten satellite communications?

Since the first attempts of people to communicate over long distances the technology employed has not only become more complex in response to the amount of information that people have wanted to send but has, curiously enough, also exhibited cyclic tendencies in the course of the evolution to the present day. Now another change is occurring with the advent of ever-larger capacity fiber optic systems, and in some circles the thought is voiced ‘what of the future of satellite communications?’ This article addresses some of the issues at play in this environment and provides a perspective for consideration.     

Globalization and commercialization of satellite broadcasting: current issues

The issues of freedom of information and protection of national sovereignty have been brought to the fore by the global spread of satellite broadcasting. This article discusses the issues and the international legal strategies that have been adopted to deal with them. It is suggested that the European model—in which states have no right to interfere with reception but broadcasters are obliged to fill 50% of their content with European programs—presents a blueprint that others could follow.     

Multi-cell satellite for the communications of year 2000

The multi-cell communication satellite concept allows an efficient use of the geostationary orbit and a large reduction of the bit transmission cost, as a Bell-type (phased array), multiple mobile narrow beams arrangement with SS-TDMA.It has a flat hexagonal flying-saucer shape, being erected in a low altitude orbit, through an automatic assembly process of a large number of quasi-identical hexagonal cells. Each cell has independent power supply, thrusters, RF modules etc….Total assembly requires 10 ARIANE V or 4 SHUTTLE launches. An automatic tooling assembly using simple iterative manoeuvers is used to obtain the final shape, from initial cylindrical packages.Transfer into geostationary orbit is provided by low-thrust bi-propellant units attached to the cells, and released after burn-out. Assembly and transfer duration is about 6 months.Total traffic to 1000–2000 towns being 100 Gbits/s, the expected reduction of bit-transmission cost relative to year 1981 is 75–100 fold.     

Developing the next phase in NASAs satellite communications program

NASAs early efforts in satellite communications development brought confidence in space technology use for improved telecommunications. New, worldwide satellite communications systems have resulted, and are now on a commercial, self-sustaining operational basis. Since 1973, NASA has conducted hundreds of user experiments and demonstrated newer technology using ATS-1, -3, -6 and CTS. Now, projections show that the commercial demand will continue to increase, soon exceeding the current technology's capacity.As a result, U.S. Space Policy affirmed in 1978 that NASA should embark again on a research and development program for satellite communications with specific, characterized goals. The resulting plan's elements include $\text{30}\text{20}\text{GHz}$ Ka-band technology, extending the current work in advanced multi-beam antennas; a narrowband system and technology study that could lead to mobile and transportable communications developments; and studies of future uses of technology in communications. The program plan and its evolution are described, followed by a report of current progress and future expectations.     

Trends in the design of future communications satellite systems

This paper presents a review of the trends in communication satellite technology. In the near term the development of moderate size, dedicated satellites is to be expected. In the long term international coordination of orbit and spectrum allocations, introduction of higher-frequency bands, spectrum conserving techniques and the concept of large communication platforms deserve particular attention. Means to improve the cost effectiveness of satellite communications system and technology aspects are considered. Finally some German contributions to these developments are presented, mainly concerning high-power TWTs in the 12 and 20 GHz range.     

移动卫星通信捷联式天线稳定系统

介绍了一种应用激光陀螺惯性导航系统组成的移动卫星通信的捷联式天线稳定系统 ,给出了天线稳定和跟踪的控制方法和最优值搜索法。采用该系统可测量载体的姿态角和经度纬度 ,借助于惯性系统的输出信号控制天线轴使天线跟踪指定的卫星 ,卫星天线接收的信号可检测出跟踪误差 ,通过伺服系统控制天线转动 ,以使通讯信号为最强。采用了 GPS修正惯性系统的误差 ,成为 GPS/ INS的组合系统。在山区道路上跑车试验结果表明 ,当车的横滚角和俯仰角达到 6°,频率为 1Hz,方位角变化 180°时 ,在此动态条件下根据测量的卫星信号场强可知 ,跟踪误差小于 0 .2°。接收到的电视信号稳定清晰 ,图像和电话信号都是满意的。跑车试验表明 ,天线跟踪卫星的静态和动态精度完全满足了移动卫星通信的技术要求     

Research and development of On-Board Processor for advanced mobile satellite communications

This paper describes the research and development of an On-Board Processor (OBP) for a mobile satellite communications system using a geostationaly satellite. The system, which based on Multi-Carrier Time Division Multiple Access, can realize high performance and facilitate the use of miniature hand-held mobile Earth terminals.

Our research and development results indicate as follows.

1. 1) The simultaneous-slot switching method will be the most suitable for an on-board base-band switching with consideration of traffic capacity, time delay, and hardware scale.

2. 2) The OBP performs channel exchange with regeneration that contributes to a reduction in the size of mobile terminals because of the coding gain.

3. 3) Many kinds of Application Specific Integrated Circuits are designed to realize large channel capacity and reduce the size and power consumption of the OBP. These OBP design can increase the channel capacity, which is equivalent to in 5.6kbps voice channel, up to over 500 channels within 5MHz frequency band

Some results are applied to the OBP being developed for the Japanese Engineering Test Satellite VII (ETS-VB).     

A Canadian system for satellite based advanced personal communications at the Ka-band

A Canadian Government program is currently under way to define, in detail, services and applications, user requirements, end-to-end system architecture and subsystem equipment design requirements for a demonstration on-board-processing (OBP) communications satellite system. The program has reached an advanced stage of definition. The prime directive of the overall mission is to provide demonstration and development of technology and services.

This paper begins by describing the development of our understanding of the true scope of advanced personal communications services and applications; the user expectations and hence terminal characteristics are also reviewed in the context of the competitive environment of other service offerings both existing and planned. In addition, the results of considerations on spacecraft complexity and hence feasibility, caused by the impact of each service option and the requirements for internetworking, are reviewed.     

Economic effect of satellite communications based on the Great East Japan Earthquake

On 11 March 2011, an undersea earthquake of magnitude 9.0, the largest ever recorded in Japan, occurred off the Oshika Peninsula on the Pacific coast of the Tohoku region. The hypocentral region extended for 500 km in the north–south direction from Iwate Prefecture to Ibaraki Prefecture, and for 200 km in east–west direction. The earthquake generated a tsunami with a height of more than 10 m and a run-up height of up to 40.0 m in certain places, which inflicted devastating damage on the coastal areas of the Tohoku and Kanto regions. In addition to the tsunami, the earthquake caused shaking, liquefaction, subsidence, and the collapse of dams, causing major damage to vast areas in the Tohoku and Kanto regions and disrupting various types of infrastructure, including communication. In light of this unprecedented damage, satellite communications were important from various perspectives while terrestrial communications systems were damaged, and an objective evaluation of the role played by satellite communications is relevant to its future installation, adoption and use as a standalone or backup system. Furthermore, satellite communications can help reduce the extent of damage, particularly damage to communications systems, inflicted by strong earthquakes in the future. Accordingly, we report a preliminary quantitative evaluation of the role of satellite communications in the Great East Japan Earthquake, of the role of satellite communications if it becomes widespread, and of its expected role in future large-scale earthquakes in terms of the economic effect converted into cost.     

国外光学成像卫星发展现状简析

光学成像侦察卫星是现代战争中信息获取的重要手段,世界上许多国家都在发展光学成像侦察卫星系统,在国际航天侦察领域也呈现了三个集团的发展态势。介绍了世界主要航天大国的光学成像侦察卫星的在轨运行、技术指标等发展现状,以及主要在研项目进展及其预期达到的能力,最后分析了其未来技术发展和军事应用趋势。     

隐身卫星的现状及其在空间攻防中的应用

空间攻防是空间技术的一个主要研究内容。隐身卫星正以独特的优势在空间对抗领域中发挥重要作用。首先论述了卫星隐身的主要手段,其次分析了国内外隐身卫星的发展现状,最后详细介绍了隐身卫星在未来空间攻防中的应用前景。     

基于在轨运行状态的卫星稳定性与可靠性研究

为解决卫星在轨运行故障率较高的问题,文章分析了卫星在轨运行的特点,定义了卫星在轨工作状态及其与系统稳定性变化的关系。研究表明:对在轨运行安全稳定状态进行控制,能使状态保持或向高级跃迁,可提升卫星稳态及可靠性。文章最后提出了提高卫星在轨运行稳定性与可靠性的在轨运行策略与技术方向。     

一种卫星用浪涌电流抑制电路的设计与分析

为防止容性设备产生的浪涌电流对整星供电系统的危害,提出一种卫星上常用的浪涌电流抑制电路,并对该电路的设计进行详细说明,最后,通过具体案例说明浪涌电流抑制电路的重要性和有效性。