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卫星通信作为一种重要的通信方式,在数字技术的迅速发展推动下,得到了迅速发展。卫星设备用来实现各种网络的互联,为家庭和商业提供互联网的接入服务。本文提出了卫星数据通信网的概念,并讨论卫星通信中的扩展TCP技术、卫星通信中的Internet业务接入等关键问题,最后描述卫星通信Internet业务接入的特点。 相似文献
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综合业务卫星通信网的设计 总被引:1,自引:1,他引:0
目前的卫星通信系统主要有FDMA/MCPC、FDMA/SCPC、MF-TDMA等技术体制,其中MF-TOMA存在明显优势,分析了帧中继接入及MF-TDMA卫星通信体制的优点。根据用户需求及网络规模,对卫星通信体制进行了选择,设计了一个支持综合业务传输的帧中继MF-TDMA卫星通信系统。对业务量计算、载波数量选择、载波速率选择等系统设计关键问题进行了重点设计。 相似文献
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综合运营交换系统是卫星运营商实现商业运营的业务支撑平台,基于业务规则引擎、工作流引擎、消息中间件以及插件技术实现的开放式综合运营交换系统,可支持多业务接入、多业务融合运营计费,简化卫星通信运营商业务办理流程,提高工作效率,满足日常运营需求。 相似文献
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Aiming at the severe challenges of access control policy redundancy and conflict detection,the efficiency of access control policy evaluation in complex network environment,an attribute-based lightweight reconfigurable access control policy was proposed.Taking the attribute-based access control policy as an example,the attribute-based access control policy was divided into multiple disjoint atomic access control rules according to the operation type,subject attribute,object attribute,and environment attribute in the access control policy.Complex access control policies were constructed through atomic access control rules and an algebraic expression formed by AND,OR logical relationships.A method for redundancy and collision detection of atomic access control rules was proposed.A method was proposed for decompose a complex access control policy into equivalent atomic access control rules and an algebraic expression.The method for redundancy and collision detection of complex access control policies were proposed through redundancy and collision detection of equivalent atomic access control rules and algebraic expressions.From time complexity and space complexity,the efficiency of the equivalent transformation access control policy was evaluated.It showes that the reconstruction method for access control policy greatly reduces the number,size and complexity of access control policy,improves the efficiency of access control policy redundancy and collision detection,and the efficiency of access control evaluation. 相似文献
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Aiming at the current problems of database access control,the thought of blockchain technology applied to database access control was proposed.The implementation mechanism of database access control based on blockchain was designed from several aspects as blockchain hierarchical structure,logical hierarchical structure of access control process,implementation principle of access control,consensus authentication principle of access control,and construction mechanism of access control blockchain system.The performance of database access control system based on blockchain was assessed.A complete framework was provided for blockchain applied in database access control.Through strengthening the authentication and supervision of visitor identity,access permission and access behavior,the database access control ability is improved effectively. 相似文献
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几种宽带接入技术比较及其应用分析 总被引:1,自引:0,他引:1
文章介绍了ADSL、以太网、光纤、无线和Cable Modem等当前主流宽带接入技术,分析了每种技术的特点和具体应用场合,最后对宽带接入技术发展进行了展望。 相似文献
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首先,在基于传统访问控制策略的基础上,针对当前互联网环境中存在的跨域访问安全问题,提出一种基于属性证书的访问控制策略。然后,给出属性证书的结构模型和管理方式,并对采用属性证书访问的优势进行分析。指出不同于传统的访问控制,基于属性证书的访问控制其本质是基于属性的访问控制。最后,给出属性证书在跨域访问控制中的应用。在单应用域或跨域访问时均可采用属性证书的验证方式,其能够针对不同应用域中用户的访问需求,动态实施资源管理和访问控制。 相似文献
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访问控制的任务是保证信息资源不被非法使用和访问,冲突检测与消解主要解决不同信息系统安全策略不统一的问题.随着计算机和网络通信技术的发展,先后出现了自主访问控制模型、强制访问控制模型、基于角色的访问控制模型、基于任务的访问控制模型、面向分布式和跨域的访问控制模型、与时空相关的访问控制模型以及基于安全属性的访问控制模型等访问控制模型.本文从理论和应用研究两个角度分析和总结了现有访问控制技术、访问控制策略冲突检测与消解方法的研究现状,提出了目前访问控制模型及其冲突检测与消解研究在面向信息物理社会的泛在网络互联环境中存在的问题,并给出了细粒度多级安全的访问控制模型及其策略可伸缩调整方法的发展趋势. 相似文献
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The article builds three engineering rural access network models that describe the structure of network elements and their relative engineering parameters for cable access、synchronous code division multiple access (SCDMA), and very small aperture terminal (VSAT) access technologies in the rural areas of China. Of the three access technologies, cable access and SCDMA access are the most popular access technologies. Besides, there still exist some remote special areas such as western mountain areas, whose natural environment is so bad that VSAT becomes the unique economical access way. Fully considering rural areas' geographical environments' impact, the article introduces geographical revised factor (GRF) to the models. By substituting the network data from the operators into the models, the article obtains the integrated networking values and does further researches on different access networks. 相似文献
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随着电信运营商重组及全业务运营的到来,电信运营商的光缆接入网络将由单一的满足基站接入向承载、接入综合业务的功能进行转变。结合移动网络的特点,提出一种光缆网络接入方式--按区域划分接入的建设方式,并详细探讨了该方式的建设、业务接入等内容。 相似文献