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本文介绍了网间互联互通现状和建设固定通信网接口局的必要性,根据网间互联互通的基本原则,探讨了固定网侧接口局建设方案。 相似文献
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6会议电视网6.1概述会议电视是现代通信技术与电视技术相结合的产物。它通过通信线路将各处一方的多个会议室连接起来 ,彼此交换语音、图像和数据信号 ,使不同地点的与会者不仅能听到发言人的声音 ,还可在屏幕上看到会场实时情景 ,使与会者有一种身临其境的感觉。会议电视作为一种多方多媒体通信业务 ,其应用范围还可拓宽到远程教学、远程医疗、居家办公等方面。6.2会议室会议电视系统的组成会议电视系统可分为会议室会议电视系统与桌面会议电视系统 ,本文只介绍会议室会议电视系统。该系统一般具有交互式会议功能 ,即在举行会议过程… 相似文献
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本文分析了网间互联互通现状和建设固定通信网接口局的必要性,根据网间互联互通的基本原则,探讨了固定通信网侧接口局建设方案。 相似文献
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多媒体会议中图像通信的不等差错保护技术实现 总被引:2,自引:2,他引:0
提出了一种在多媒体会议图像数据传送中使用Reed Solomon码的交织不等差错保护新方法.这种方法提高了组播会议终端重建多媒体的质量,并在克服网络突发错误方面有较好效果,提高了网络传输的性能. 相似文献
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Smart grid technology has attracted a lot of attention in the communication and power engineering communities because of its high efficiency and environmental friendly power production and delivery. Smart grid communication networks act as not only a bridge between the end power users and the utility but also a backbone of the entire smart grid system. It is a challenging task to deploy smart grid communication networks because of interference‐intensive environment. The goal of this paper is to explore various issues on deployment of smart grid communication networks. The first half of this paper provides a survey on smart grid communication networks. The background of smart grid communication networks is introduced, and the IEEE 802.15.4g standard for smart utility networks is reviewed. In addition, the issues on network topology and routing protocols of smart utility networks are addressed, followed by the discussions on optimizing gateway deployment. Various methods for addressing coexistence issues in smart grid communication networks are presented. The second half of this paper is to propose a channel discovery algorithm exploiting the inherent CSMA/CA mechanism in the protocols. Because of the use of CSMA/CA mechanism and up‐to‐date channel status table, the proposed algorithm can quickly find an available channel for transmission when interferences occur. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Peter King Ramachandran Venkatesan Cheng Li 《Wireless Communications and Mobile Computing》2010,10(11):1521-1532
Development of communication channels for underwater sensor networks holds many unique challenges. Communication near the bottom of the ocean is no exception as the effects of reflection and refraction greatly affect how acoustic waves travel between a source and an intended receiver. Deployment and testing in the ocean are difficult and expensive; thus there is a strong reliance on models to aid in design and development of a potential network. Since each ocean region can present very unique challenges, it is of great value to model an environment based on real environmental parameters whenever available. A well prepared channel model will provide the ability to show channel capacity as it relates to node positions, as well as showing the performance of modulation techniques to an environment with propagation characteristics and path arrivals. This channel model will also be implementable into a simulation package to allow for high quality simulation of higher level protocols. The proposed method has proved to be a useful tool in modeling a particular environment and provides insight into underwater sensor node placement and modulation. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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通过对无线通信频率指配问题的分析,结合遗传算法在频率指配领域的应用,提出了一种启发式的指配方法。该方法通过改进选择方式,自适应地调整交叉、变异概率来指配信道分配。仿真分析证明,该算法科学可行,有效地避免陷入局优解,加快了种群进化速度,减少了迭代次数,较快收敛到最优解。 相似文献
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机动干线通信网具有机动、灵活、多变性,对网络的抗毁性、可靠性、生存性有着特殊的要求。针对机动干线通信网的特点,提出一种快速评价网络整体抗毁性的方法,给出抗毁性定量计算的数学解析式,同时给出网络中各节点、链路对网络抗毁能力的贡献量度。建立合理、有效的抗毁量度指标对机动干线通信网络优化、网络调整以及网络评估都有着重要意义。 相似文献