Space for celestial symphonies? Towards the establishment of international radio quiet zones

The growth of low- and medium-Earth orbit mobile satellite communications poses a threat to radio astronomers which could be mitigated by the establishment of international radio quiet zones (IRQZs), where communications traffic is managed (not eliminated) to allow radio astronomy to continue. Using the prototype of national such zones in the USA, this article explains how the system would work and discusses the international legal parameters that would bound it, drawing on current aerospace, outer space and high seas legislation. Precedents for an IRQZ—Exclusive Economic Zones, denuclearised zones and the Antarctic regime—are also examined.     

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.     

W波段行波管及卫星通信系统应用前景

为了满足卫星系统对通信容量日益增长的需求,W波段已经成为空间通信应用中的前沿。对于高功率放大器,w波段行波管在输出功率和工作带宽方面具有优势,国内的W波段连续波和脉冲行波管在功率和带宽等主要技术指标上已经达到国际先进水平,希望进一步提高器件的实用化程度和可靠性,促进W波段卫星通信系统的研究,为我国下一步高频率宽带卫星通信系统达到国际先进水平提供自主可控的核心电子元器件产品。     

Pakistan's space programme

Space research in Pakistan is conducted by the Pakistan Space and Upper Atmosphere Research Commission (Suparco). Suparco's programmes consist of the launching of sounding rockets and satellite applications, especially remote sensing and communications. Its long-term goals are to develop communications and remote sensing satellites and to launch lightweight scientific satellites in near-Earth orbits. To train its scientific staff at postgraduate level, Suparco is establishing an Aerospace Institute. The Commission is very active in international forums such as the UN COPUOS, Cospar, IAF and IUCN.     

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.     

Telecommunications and the economic impact of communications satellites

This article provides several illustrations of the growing economic importance and scope of communications satellite service and discusses how rapid development of new telecommunications systems, particularly those that include communications satellite systems, serve as a major stimulant of economic growth. There is evidence that communications satellites are capable of making important economic contributions to developed and developing countries alike. The rapid proliferation of separate communications satellites, although stimulating economic growth, is giving rise to concerns about intersystem connectivity and saturation of the available radio frequencies in geosynchronous orbit. The growth of the communications satellite industry to an activity level of perhaps $10,000 million per annum by the mid-to-late-1980s could assist in the development of multipurpose space platforms that could minimize the problems created by satellite proliferation.     

PFI in the sky, or pie in the sky? — Privatising military space

The UK has made use of dedicated, national military satellites for communications since November 1969. The replacement of the current system, Skynet 4, which will reach the end of its design lifetime early in the next century, is currently under consideration. Possible options which have been mooted to date include a new generation of a national satellite system (Skynet 5), or one of several international collaborative projects. However, these appear to have been superseded by a new possibility — a privately, commercially funded national system under the government's Private Finance Initiative (PFI). This paper examines the historical reliance of the UK on military satellite communications, the options for the next generation of such systems, and, drawing on the UK example, raises a number of questions concerning the potential significance of reliance on commercial enterprise to provide a key element of defence capability.     

Results of Kirari optical communication demonstration experiments with NICT optical ground station (KODEN) aiming for future classical and quantum communications in space

Bi-directional ground-to-satellite laser communication experiments were successfully performed between the optical ground station developed by the National Institute of Information and Communications Technology (NICT), located in Koganei City in suburban Tokyo, and a low earth orbit (LEO) satellite, the “Kirari” Optical Inter-orbit Communications Engineering Test Satellite (OICETS). The experiments were conducted in cooperation with the Japan Aerospace Exploration Agency (JAXA), and called the Kirari Optical communication Demonstration Experiments with the NICT optical ground station (or KODEN). The ground-to-OICETS laser communication experiment was the first in-orbit demonstration involving the LEO satellite. The laser communication experiment was conducted since March 2006. The polarization characteristics of an artificial laser source in space, such as Stokes parameters, and the degree of polarization were measured through space-to-ground atmospheric transmission paths, which results contribute to the link estimation for quantum key distribution via space and provide the potential for enhancements in quantum cryptography on a global scale in the future. The Phase-5 experiment, international laser communications experiments were also successfully conducted with four optical ground stations located in the United States, Spain, Germany, and Japan from April 2009 to September 2009. The purpose of the Phase-5 experiment was to establish OICETS-to-ground laser communication links from the different optical ground stations and the statistical analyses such as the normalized power, scintillation index, probability density function, auto-covariance function, and power spectral density were performed. Thus the applicability of the satellite laser communications was demonstrated, aiming not only for geostationary earth orbit-LEO links but also for ground-to-LEO optical links. This paper presents the results of the KODEN experiments and mainly introduces the common analyses among the different optical ground stations.     

Commercial Opportunities for Broadband Maritime Satellite Communications in the Era of HTS Satellites

Compared with the ever-changing development and changes of land communications,the development of maritime communications lags behind slightly,particularly on the offshore platform due to the complex and changeable environment,as well as the extremely difficult construction.However,the development of High Throughput Satellite(HTS)has changed the market pattern for traditional satellite communications,and its advanced technology concept ensures the rapid growth of maritime communications business.This article mainly analyzes the demand and current status of maritime satellite communications,discusses and expounds the commercial opportunities HTS satellites will bring to the era of maritime communications satellite.     

Satellite-aided land mobile radio experiments,applications and problems

Radio communications between vehicles or individuals and base stations are essential to many public safety, law enforcement and commercial users in urban areas. Present day communications are limited to nearly line-of-sight distances from the vehicle or hand portable units to a base station or repeater. It is probable that many potential users in rural, remote and offshore areas would benefit if the communications were available everywhere on land and territorial waters. Geosynchronous satellites can serve as repeaters for mobile and personal radios, and they appear to be a cost effective means of providing the service.Voice bandwidth communication and automatic position monitoring of an automobile were tested using the VHF transponders of NASAs ATS-3 and ATS-1 satellites. Voice communications were reliable and position fixes were accurate to one fourth mile, with 0.3 mile precision of individual fixes.Demonstrations for potential users have included emergency medical voice and telemetry communications between ambulances and hospitals.While technical feasibility of satellite-aided mobile and personal communications has been demonstrated, and its potential value is appreciated by a small segment of the user community, many problems remain before an operational system could be implemented. Solutions to the problems require an experimental satellite with a multibeam antenna. The satellite or its associated ground terminals should incorporate computer controlled network switching to test demand assignment of channels. Prolonged experience by many users of the experimental satellite in their routine operations would aggregate user needs and define the capital investment that would be justified to implement a commercial operating system.     

无人机在干扰卫星通信系统中的应用

随着军事信息化程度越来越高,军事卫星通信已成为军事通信和战场通信的重要组成部分。卫星通信干扰和抗干扰技术已受到各国的重视。文章首先分析了干扰卫星通信系统的几种途径,然后分析了无人机在干扰卫星通信系统中的应用及优势。     

卫星通信发展及与地面移动通信融合思考（英文）

With the further reduction in cost and the increase in bandwidth, as well as the increase in internet applications, satellite communications are gradually shifting from a complementary role to becoming a fully integrated component of terrestrial communications networks. This paper firstly introduces the development of satellite communications, mobile communications and the global space-terrestrial integrated network. We then propose the functional architecture and network architecture for the integration of satellite communications and terrestrial mobile communications based on 5 G core networks. Finally, in order to support the network of the future, four key technologies are presented, a space-terrestrial integrated air interface design, a multi-band space-terrestrial integrated transmission waveform design, space-terrestrial integrated switching and routing technology, along with spectrum sharing and interference coordination technology, all necessary for the development of space-terrestrial integrated networks.     

Learning via satellite

This report describes a global applied research project — Project Learn — being sponsored by the International Space University in Strasbourg, which aims to address key educational needs, particularly in remote and rural areas, via satellite. The project aims to bypass conventional approaches to education, health care and communications development by using global information technologies at a local level and drawing a range of international organizations into a cooperative effort. Examples of the kind of work to be undertaken by the project are presented.     

Ukrainian space policy — contributing to national economic development

Following Ukraine's 1991 declaration of independence and the disintegration of the USSR, Ukraine inherited a third of the Soviet Union's space industry. This paper presents an overview of the main features of Ukraine's current policy on the exploitation of this capability as a factor in the transformation of its economy. It illustrates how the policy is being realized in the areas of launch systems, Earth observation, satellite communications and international relations, and concludes that Ukraine's strengths in the space field are counterbalanced by obstacles which must be faced, both within the country and externally.     

星地测控对接手段探析

星地测控对接试验常用的手段有三种：真星产品对接、专用测控模拟器对接、通用测控模拟器对接。文章从静止轨道通信卫星入手,介绍星地对接项目以及这三种对接手段的组成、特点和可对接项目,并通过对这三种对接手段在成本、研制周期、对接真实性等方面的比较分析,给出这三种对接手段所适宜应用场合的结论。     

Space technology in developing nations: an assessment

Space technology can make an immense contribution to solving the problems of the world as a whole, and the developing nations in particular. This report summarizes the use of satellites by developing countries in the fields of communications, remote sensing, disaster management and space science. India and China, in particular, have built up impressive capabilities in several of these areas, but the great majority of developing countries still do not have access to this technology. The author addresses a number of proposals to the international community for bringing the satellite revolution to the developing world.     

鹊桥中继通信卫星在轨运行一年（英文）

Queqiao relay communications satellite was developed to provide relay communications services for the lander and the rover on the far side of the moon. From entering into its halo mission orbit around the Earth-moon libration point 2 on June 14, 2018, it has operated on orbit more than fifteen months. It worked very well and provided reliable, continuous relay communications services for the lander and the rover to accomplish the goals of Chang'e 4 lunar far side soft landing and patrol exploration mission. The on-orbit operation status of Queqiao relay communications satellite is summarized in this paper.     

同步串行总线在通信卫星转发器中的应用

提出了一种适用于通信卫星转发器分系统测控数据传输的5线制同步串行总线,支持30个终端同时接入,改变了通信卫星平台传统的点对点式的遥测遥控信息传输方式,大大减少了通信舱内电缆数量;并在某通信卫星载荷舱上进行了应用,使卫星载荷舱质量减少几十千克,提升了卫星平台的有效载荷能力。文章设计的串行总线提供标准的接口电路,有利于有效载荷设备的扩容,可以推广至更多的有效载荷设备,构成其之间的测控信息网络。     

Status and prospects of China''s space programme

This article presents the current status and characteristics of China's space programme before describing the country's future goals and the specific types of research and satellite production that will be undertaken to realize them. China's programme, although small, has achieved much in terms of economic and social benefits for its people (eg through land-surveying, communications, education, water conservation and earthquake prediction). This is a result of the emphasis place on applied-satellites, coordination of production, development and research and intensive ground testing. This emphasis will remain, along with the effort to ensure that new satellites are long-lived and stable in operation. However, a change from the previous policy of independence is signalled by a growing interest in international cooperation, including that with other developing countries like Brazil.     

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.