space communications and internet

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Diego, USA, in the Globalstar LEO project system group under an ESA fellowship. His current interest is mainly related with efficient digital modulation and ...
GUEST EDITORIAL

SPACE COMMUNICATIONS AND INTERNET

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Riccardo De Gaudenzi

YANG Qianli

O p a c e is a vast and important territory that has been ^ studied and explored by humans for centuries. Since the first man-made satellite was launched in 1957, thousands of projects involving space probes and their utilization have been implemented. Many kinds of satellites are currently used for communication, broadcasting, earth observation, navigation, and deep-space exploration, etc. Because of their unique features referred to as "stay high and cover wide", satellites are considered to be irreplaceable because of the functions that they perform, and spacecraft require various kinds of communications. Over the past few decades, there have been various efforts to build a space Internet for deep space exploration purposes. We have therefore established this special issue, and to date, we have received a total of 52 manuscripts from authors worldwide. After careful review, we have selected and present 5 papers for our readers. The first three articles are related to the field of deep space networks. The paper by GOU Liang, ZHANG Gengxin, BIAN Dongming, XUE Feng and HU Jing titled "Relay Scheme Based on Distributed Luby Transform Codes for InterPlaNetary Internet' proposes Full Distributed Luby Transform Codes (FDLT) which can fully utilise the source symbols to reduce the overhead and improve the energy efficiency at sources, while keeping a low overhead at the relay. Delay Tolerant Networking (DTN) originated from research on Interplanetary Internet Networking (IPN) involving Internet pioneer Vint Cerf et al., and related to the need for networking technologies that can cope with the significant delays and packet corruption associated with deep-space communications. The paper by Pietrofrancesco Apollonio, Carlo Caini and Vincenzo Fiore titled "From the China Communications · October 2013

Far Side of the Moon: Delay/Disruption-Tolerant Networking Communications via Lunar Satellites" investigates DTN communications between the Earth and the far side of the Moon, and uses a lunar orbiter acting as a relay. The paper presents a comprehensive analysis of the DTN performance that can be achieved in the identified Moon communication scenario. This paper focuses on the evaluation of the state-of-the-art capabilities of the Interplanetary Overlay Network (ION), which is the NASA DTN's implementation of the Bundle Protocol (BP) and Contact Graph Routing (CGR), to meet the many challenges of the space communication scenario that was investigated. The paper from XU Ying and YUAN Hong which was titled "High-Sensitivity Acquisition of Ultrahigh Dynamic Direct Sequence Spread Spectrum Signals in Space Communications", deals with the issue of the acquisition of a Direct-Sequence Spread-Spectrum in highly dynamic link conditions. This corresponds to telemetry, telecommand and control links operating at a high carrier frequency (e.g. Ka-band) with fast moving space vehicles causing a high Doppler rate. In such extreme operating conditions, conventional signal acquisition techniques are prone to failure. In this paper, the authors propose a novel high-sensitivity acquisition algorithm suitable for an ultrahigh dynamic environment based on a joint search of the Doppler frequency and its rate-of-change. The LEO constellation has been comprehensively studied and continues to attract much attention. The fourth article, "Cross-Layer Design and Ant-Colony Optimization Based Routing Algorithm for Low Earth Orbit Satellite Networks" by WANG Houtian, ZHANG Qi, XIN Xiangjun, TAO Ying and LIU Naijin focuses on improving the robustness of Low IX

GUEST EDITORIAL

Earth Orbit (LEO) networks and realising load balancing. Mobile agents are used to actively gather routing information. Then, the network can utilise the information of the physical layer to make routing decisions during the route construction phase. The issue of integration between terrestrial and satellite mobile networks is facing new challenges with the advent of fourth generation (4G) mobile systems. The paper which was co-authored by LIU Siyang, QIN Fei, GAO Zhen, ZHANG Yuan and HE Yizhou, and which is titled "LTE-Satellite: Chinese Proposal for Satellite Component of IMT-Advanced System" provides an overview of the required adaptations to the terrestrial mobile Long Term Evolution (LTE) 4G 3GPP standard to enable it to be exploited by a geostationary satellite-based mobile network. The satellite LTE standard will be able to complement the terrestrial networks coverage with an air interface derived from the terrestrial LTE standard with ad-hoc modifications. The Chinese LTE-satellite proposal described in this paper is a candidate for the International Telecommunication Union International Mobile Telecommunications (IMT)-advanced call for proposals. We want to thank all of the authors who submitted papers to this "Space Communications and Internet" special issue. Unfortunately, due to limited space, we are not able to publish more manuscripts at this time. However, we have reserved some of the 52 submitted papers for regular publishing at a later date. Thanks also to all the reviewers for their hard work and very good comments. We believe that with the increasing human exploration activity throughout the universe, there will be more research into space communications and space Internet. We look forward to the next feature issue on this subject in coming years.

Biographies YANG Qianli, born in Jiangyin, Jiangsu, China in October 1933. He enrolled in Nanjing University, China in 1950 and graduated in 1953.

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From 1956 to 1969 he was a teacher on wireless engineering of universities in Zhangjiakou, Xi'an and Chongqing, China respectively. During the "Great Culture Revolution" in China, in 1970 and 1971, he had physically laboured as a cowboy in "May 7th Cadre School", Xuchang, Henan, China. From 1971 to 1980, he was in Institute of Communication and Computer Engineering, China. Since then, he involved in many China's satellite communication programs from the very beginning till now. He was Vice-Chairman and Sub-Committees' Director of China Institute of Electronics (CIE), also the Directors of several committees of China Institute of Communications (GC). In the early 21th Century, he was Satellite Communications Coordinator in the United Nations Economic and Social Commission for Asia and the Pacific (ESCAP). He is IEEE life senior member and President (1996/1997) of IEEE Beijing Section. Since 1999, he is the Chairman of yearly event "China Satellite" (Conference and Exhibition) (CIC) for 15 years. Riccardo De Gaudenzi, was born in Italy in 1960. He received his doctor engineer degree (cum Laude) in electronic engineering from the University of Pisa, Italy in 1985 and his Ph.D. degree from the Technical University of Delft, the Netherlands in 1999. From 1986 to 1988, he was with the European Space Agency (ESA), Stations and Communications Engineering Department, Darmstadt, Germany, where he was involved in satellite telecommunication ground systems design and testing. In 1988, he joined ESA's Research and Technology Centre (ESTEC), Noordwijk, the Netherlands, where since 2005 he is the Head of the Radio Frequency Systems, Payload and Technology Division. The division is responsible for supporting the definition and development of advanced satellite system, subsystems and related technologies for telecommunications, navigation and earth observation applications. In 1996, he spent one year with Qualcomm Inc., San Diego, USA, in the Globalstar LEO project system group under an ESA fellowship. His current interest is mainly related with efficient digital modulation and multiple access techniques for fixed and mobile satellite services, synchronization topics, adaptive interference mitigation techniques and communication systems simulation techniques. He actively contributed to the development and the demonstration of the ETSI S-UMTS Family A, S-MIM, DVB-S2, DVB-S2x, DVB-RCS2 and DVB-SH standards. From 2001 to 2005, he has been serving as Associate Editor for CDMA and Synchronization for IEEE Transactions on Communications. He is currently an Associate Editor for Journal of Communications and Networks. He is co-recipient of the 2003 and 2008 Jack Neubauer Memorial Award Best Paper from the IEEE Vehicular Technology Society.

China Communications · October 2013