面向全球能源互联网的天空地协同卫星通信网络架构

全球能源互联网的监测、调度、授时、同步及定位等业务均需要能提供广域覆盖、泛在灵活接入服务的可靠通信网络。针对该需求,首先分析阐述全球能源互联背景下各种新型业务需求及其特点,并总结各种业务的共性数据特征;然后论述卫星通信技术的特点以及与全球能源互联网业务特点与数据传输需求的高度契合性,最终提出融合卫星通信网络的全球能源互联网天空地协同网络体系架构。其以IP技术为基础,各层网络通过星间、星地、星空、空空、空地以及地面有线、无线链路连接起来,构建全球覆盖的一体化网络体系。     

天地一体化信息网络在我国民航领域的应用设想

天地一体化信息网络工程将构建全球覆盖的安全、高效、实时、宽带数据传输网络,基于天地一体化信息网络的新一代机载通信、导航、监视系统是未来我国民用航空电子系统发展的重要趋势之一,可以显著提升机载航电系统能力,为航空运输的安全性、经济性、环保性、舒适性带来巨大的变革。在分析国外航空卫星系统在民用航空领域应用现状的基础上,针对我国天地一体化信息网络在民用航空领域的应用差距,提出了基于我国自主卫星系统的天地一体化信息网络在民用航空领域应用的建设设想、实施步骤及适航考虑。     

基于边缘智能协同的天地一体化信息网络研究

随着应用需求的发展，如何在天地一体化网络的异构组网环境中以及大时空尺度下提供高效的网络服务成为新的挑战。基于对未来天地一体化信息网络需求的分析，提出一种未来天地一体化网络架构——基于边缘智能协同的天地异构融合标识网络架构，介绍了架构的 3 种关键技术，即服务标识建模及分发机制、异构网络资源深度自感知机制和天地异构网络协同融合机制。最后，介绍了所提架构在高铁通信、民航通信、普惠服务以及特种通信场景中的应用前景。     

关于天地一体化信息网络典型应用示范的思考

天地一体化信息网络通过多轨道卫星星座将陆基、海基、空基网络连接起来,构成覆盖全球的一体化通信网络,可以为我国海洋、航空、航天、信息普惠、商用全球宽带通信等多种应用场景提供全新的解决方案,为“一带一路”等国家战略实施提供通信应用及服务支撑。在充分汲取国际先进技术、产业和应用服务经验的基础上,通过开展典型应用示范系统的建设,可以进一步验证天地一体化信息网络的能力,牵引出更多应用需求和商业模式,并就未来天地一体化信息网络典型应用系统的建设提出了一些初步的考虑和设想,为全球各类用户提供基础公共服务及专业服务。     

自适应光学对星地相干激光通信性能改善研究

相干激光通信能够实现每秒数百吉比特的通信速率和接近量子极限的灵敏度,在未来天地一体化信息网络中具有广泛的应用前景。大气湍流引入的光学波前畸变是影响星地相干激光通信链路性能的重要因素。本文将自适应光学技术应用于大口径光学地面接收站,并系统地开展了4 Gbps高速相干激光通信试验,试验结果表明,自适应光学技术能够有效抑制中等大气湍流的影响,并提高相干激光通信的灵敏度和稳定性。     

天地一体化信息网络统一编址与路由研究

天地一体化信息网络将是支持地面互联网、无线移动网络和空间网络相互连通、深度融合的一体化网络,采用统一的网络层设计是实现高效融合与互联互通的关键所在。针对空间链路和空间网络在稳定性、可靠性等方面的特点,提出了天地一体化信息网络的统一编址与路由的方案,基于IPv6和层次路由的方式实现网络层的高效融合,具有良好的可扩展性、可用性、稳定性、可管控性。     

Proxy re-encryption based multi-factor access control scheme in cloud

Cloud computing is one of the space-ground integration information network applications.Users can access data and retrieve service easily and quickly in cloud.The confidentiality and integrity of the data cloud have a direct correspondence to data security of the space-ground integration information network.Thus the data in cloud is transferred with encrypted form to protect the information.As an important technology of cloud security,access control should take account of multi-factor and cipher text to satisfy the complex requirement for cloud data protection.Based on this,a proxy re-encryption based multi-factor access control (PRE-MFAC) scheme was proposed.Firstly,the aims and assumptions of PRE-MFAC were given.Secondly,the system model and algorithm was defined.Finally,the security and properties of PRE-MFAC were analyzed.The proposed scheme has combined the PRE and multi-factor access control together and realized the multi-factor permission management of cipher text in cloud.Meanwhile,it can make the best possible use of cloud in computing and storing,then reduce the difficulty of personal user in cryptographic computing and key managing.     

Cross-network access control mechanism for complex network environment

Complex network environments,such as space-ground integrated networks,internet of things and complex private networks,have some typical characteristics,e.g.,integration of multi-network and information flow in cross-network.These characteristics bring access control for complex network environment the new requirement of coarse-grained control,sticky policies and inconsistent operation semantics.To satisfy these requirements,cross-network access control mechanism in complex network environments (CACCN) was designed by mapping the cyberspace-oriented access control.First of all,the process of mapping was illustrated using the example of space-ground integrated networks.Next,a management model was proposed to manage the control elements in CACCN and a series of management functions were designed by using Z-notation.The analysis on practical example demonstrates that the mechanism can satisfy a series of access control requirements.     

关于天地一体化信息网络发展建设的思考

在维护和拓展国家利益时,我国信息网络一直面临着“覆盖出不去、信息难兼容、服务响应慢、安全有隐患”的困境,建设天地一体化信息网络,是应对挑战的有效途径.基于此,分析了国内外相关天地一体化信息网络系统发展现状及趋势,给出了天地一体化信息网络体系结构设想、关键技术和实施策略.     

天地一体化信息网络安全防护技术的新思考

天地一体化信息网络是国家面向2030的重大科技工程,安全防护是保障其运行的关键。由于能够主动适应用户、网络和业务的快速变化,可以实现网络技术与安全的共生演进,天地一体化信息网络成为近年来国内外学术界和产业界普遍关注的重要方向。在分析天地一体化信息网络面临的安全威胁和现有防护技术思路的基础上,探讨了内生式安全防御技术在天地网络架构、关键信息系统中的应用设想,相关技术思路和设计可为内生安全的天地一体化网络安全防护体系建设提供参考。     

Integrating the scene length characteristics of MPEG video bitstreams into a direct broadcast satellite network with return channel system

In order to optimize the network resources, we should incorporate all the available information into the network design. However, incorporating irrelevant information may increase the design complexity and/or decrease the performance of the network. In this paper, we investigate the relevance of integrating the scene length characteristics of moving pictures expert group (MPEG) coded video bitstreams into a direct broadcast satellite (DBS) network with return channel system (DVB‐RCS). Due to the complexity of the studied system, unless disputable simplifications are made, it is hard to achieve a mathematical foundation for this integration. Our analysis relies on extensive set of simulations. Firstly, we achieve the scene length distributions for MPEG bitstreams based on the proposed scene change models and their subjective observations of the actual video. We show that these models may be used to estimate the scene length of MPEG bitstreams. We then integrate this estimation into a DBS network simulator. Finally, we show that the scene length characteristics may be used to improve the DBS network performance under certain conditions. Copyright © 2004 John Wiley & Sons, Ltd.     

Research status and development trends of security assurance for space-ground integration information network

Space-ground integration information network consists of space-based backbone network, space-based access network, the node net of foundation, Internet, mobile communication network, which has important significance for the realization of the target of national security strategy. Firstly, the characteristics of space-ground integration network, such as exposed channel, heterogeneous network integration, etc, were analyzed. Also, the corresponding threats from the physical layer, operation layer, data layer were introduced. Secondly, a comprehensive study on current status of surviv-ability, anti-jamming, secure access, secure routing, secure handoff, secure transmission and key management were made. Finally, combined with research status, the important trends were proposed.     

Parallel data transmission for navigation satellite network with agility link

The topology of the navigation satellite network with agility link evolves with chain‐building slots periodically. The navigation data are transmitted in a “store, carry and forward” manner without requiring end‐to‐end paths. Thus, the navigation satellite network with agility link can be considered as a deterministic delay tolerant network (DTN). The data transmission of navigation satellite network is limited by chain‐building slot and bandwidth. To utilize network transmission link and communication bandwidth fully, this paper proposed an algorithm called parallel data transmission for the navigation satellite network with agility link. Based on the network characteristics, the algorithm is designed with polling pattern of link establishment and formulated as parallel data transmission problem based on deterministic scheduling DTN. Then, we design the method based on Dynamic Game from the view of data, while the Dynamic Programming method is proposed referring to Linear Programming–based method for optimization. Finally, the results were compared with three methods using the standard network routing metrics and showed that the proposed algorithm is better than the existing methods.     

激光链路中继卫星系统网络设计及性能分析

随着卫星激光通信技术的发展,激光链路中继卫星系统将成为未来天基信息系统的骨干网。首先设计了一种2颗国土星+2颗境外星的网络架构,然后借助地面程控交换技术分析方法,定义了光网络性能指标,最后仿真了激光链路中继卫星系统的网络性能。仿真结果表明,当每颗用户卫星通信业务量为0.2 Erl、接入损失概率要求不大于0.2、链路利用率不小于0.6的情况下,激光链路中继卫星系统的12条接入链路可以支持50颗用户卫星接入。     

天基信息网络的软件定义网络应用探析

现有各种空间、地面网络节点的互连互通,在一定程度上可满足特定应用需求,但由于各节点在空间、物理以及功能的局限,限制了天基信息高效传输、融合以及按需地应用。分析了天基信息网络的发展趋势,提出了网络架构构想,并对主要关键技术的研究方向进行了梳理。在空间核心节点上采用软件定义的多功能载荷平台,并基于软件定义网络( SDN)架构和空间容中断网络协议构建天基信息网络。通过资源虚拟化、处理多元化、应用无阻化的方式,保障天基信息网络适应信息按需定制和高效共享等应用需求。     

天地一体化信息网络激光通信系统发展设想

空间激光通信技术具有通信速率高、保密性好、抗干扰能力强等优点,成为近年来的研究热点,并相继在天基信息网络中得到广泛应用。首先对国际激光通信技术的发展态势进行了分析,然后从我国天地一体化信息网络的需求出发,对不同的应用场景上的激光通信系统进行了分析,提出了我国天地一体化信息网络激光通信系统发展的建议。     

ASSESSMENT OF A PUBLIC MOBILE SATELLITE SYSTEM COMPATIBLE WITH THE GSM CELLULAR NETWORK

The integration between cellular networks and satellite systems is a very promising issue, since it permits the immediate provision of the radio services offered by the cellular networks to areas lacking in terrestrial facilities. In this paper the viability of a full integration between the GSM cellular network and a satellite system is dealt with. The L-band land mobile payload has been assumed as a reference; nevertheless the presented results can be extended to other payloads. The basic requirement of full integration is that the insertion of the satellite system does not entail any modification of the already existing GSM network. The integration analysis has been carried out by examining both the link feasibility and the network architecture. As far as link feasibility is concerned, the analysis is performed by means of an ad hoc simulation tool developed at CSELT (Turin). The simulation results are displayed for GSM speech channels at both full-rate (TCH/FS) and half-rate (TCH/HS). Such results are used in order to compute the satellite link budgets and the satellite system capacity. The characteristics of the satellite propagation channel, of the satellite-compatible mobile station and of the reference payload are explained as well. As far as the network architecture is concerned, the paper identifies the most promising satellite system configuration and the satellite system counterpart of the GSM functional areas (cell, location area, MSC area). Moreover, the problems and the relevant solutions related to the extension of the main GSM procedures (e.g. call set-up, cell selection/reselection, handover) to the integrated network are dealt with. This paper is based upon the work performed by the authors in the framework of the European Space Agency (ESA) study: ‘Assessment of a public mobile satellite system compatible with the GSM cellular network’, Telespazio (Rome) is the prime contractor of this study. The opinions herewith reported are not necessarily those of ESA.     

Emulation platform for inter-domain protocols validation of integrated space-terrestrial network

The inter-domain routing protocol is a key factor in the rapid integration of various satellite systems and heterogeneous networks in integrated space-terrestrial network (ISTN).However,the wide difference between network topologies of space and terrestrial networks may present significant challenges to the deployment of existing inter-domain protocols.To test the performance of these protocols,an emulation platform for ISTN was designed to efficiently emulate the dynamic and large-scale space network and the existing terrestrial networks using virtual network technology.Extensive experiments demonstrate that,with the expansion of the scale of space network and the scale of terrestrial Internet’s routing table,the integration efficiency between space and terrestrial networks becomes very low.     

一种基于卫星IP网络的数据链路层协议

通过分析卫星通信网络发展趋势,阐述卫星网络中现有的数据链路层协议,梳理归纳卫星网络的特点及影响,提出了一种新型卫星网络数据链路层协议(New Satellite Link Protocol,NSLP)。分析对比表明,该协议能够有效降低链路层报头开销,提高信息传输效率。在实际应用中,新型协议具有能够简化数据链路层的功能,有与TCP/IP协议兼容性好、与IP协议耦合度高、节约星上资源等诸多优点,有利于卫星IP网络整体性能的有效提升。     

卫星相干激光通信系统与技术发展

自由空间光通信(Free Space Optical Communication,FSOC)尤其是基于相干体制的卫星激光通信,正逐渐成为突破微波通信瓶颈、建设天地一体化网络、实现高速数据传输的重要手段.总结了欧空局、德国、日本及国内卫星相干激光通信的重要进展,给出了成功验证的相干激光通信系统的激光器、传输速率、多普勒频...