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扼要综述了高速公路通信网建网的总体技术要求,提出了网络的总体架构、技术方案和业务接入方式,为高速公路通信网的建设提供了参考。 相似文献
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文章介绍了北京地区数字通信网及其同步网的现状,提出了组建新的同步同方案和组网原则.介绍了网中一级基准时钟及二、三级节点时钟配置情况以及监测站的设置,介绍了网中所采用的新设备、新技术情况.包括频率改正器、GPS和LORAN—C系统、通信楼定时分配系统、同步检测系统等工作原理。 相似文献
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数字同步网是现代通信网的一个必不可少的重要组成部分,它为各种数字业务网提供定时,用以保障各种数字业务网的信号质量,是通信设备、系统、网络正常运行的重要保障。 相似文献
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阐述了通信网时间同步问题意义。分析了时间同步技术的关键点,研究了IP网上NTP协议在省级通信网时间同步的方案。 相似文献
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通信网络对时间同步的需求日益迫切,因此,必须要尽快构筑合理的时间同步网络,以便经济、合理、安全地为其提供精确的时间同步信号,本文首先对时间同步组网方案进行了研究,最后对部分时间同步业务应用进行了分析探讨。 相似文献
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于佳亮 《电信工程技术与标准化》2016,(7):31-35
针对通信时间同步网的关键性能指标,对比国内外相关技术标准的差异,并结合通信技术和业务发展对于同步性能的需求,探讨时间同步网端到端同步性能指标分配模型、时间偏差值限定等。 相似文献
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通信局房电源系统蓄电池后备时间的探讨 总被引:1,自引:0,他引:1
随着高功率密度通信设备的应用,按照现行的相关规范配置蓄电池,通信局房蓄电池的配置容量越来越大,占用了大量的机房空间,给机房的规划建设带来的许多问题.本文将通过对通信局房电源系统蓄电池后备时间的探讨,给出蓄电池后备时间配置合理性的建议. 相似文献
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针对典型的时间同步算法应用到多跳拓扑网络时存在时间同步精确度差、收敛速度慢、功耗较大等问题,文章提出一种基于分簇的多跳无线传感网络时间同步算法。该算法结合了TPSN算法和RBS算法的同步思想,摒弃了TPSN算法同步周期长的缺点而保留了其同步精确度高的优点,也解决了RBS同步开销大和难于应用到多跳网络的问题。该算法具有相当高的同步精度,并有效降低了同步功耗,具有一定的实用性。 相似文献
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In a wireless powered communication network (WPCN), sensor nodes harvest energy to transmit information. By a harvest‐then‐transmit (HT) protocol, nodes can be classified into either energy receiving (ER) or data transmitting (DT) nodes depending on the current level of the harvested energy. Since nodes may join or leave a network any time and energy levels vary, the distribution of ER and DT nodes changes over time. As the number of contending DT nodes is highly dynamic, a quick learning mechanism is required for an access point (AP). We propose a learning AP that learns from experience and adapts the frame size according to the changes in the number of DT nodes. The proposed learning AP is also shown to learn well and react to the situation. We compare the performances of the proposed learning mechanism with a WPCN and conventional HT FSA schemes. The proposed RL scheme outperforms the comparative schemes in terms of success rate and delay. 相似文献
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Secure group communication in wireless mesh networks 总被引:1,自引:0,他引:1
Wireless mesh networks (WMNs) have emerged as a promising technology that offers low-cost community wireless services. The community-oriented nature of WMNs facilitates group applications, such as webcast, distance learning, online gaming, video conferencing, and multimedia broadcasting. Security is critical for the deployment of these services. Previous work focused primarily on MAC and routing protocol security, while application-level security has received relatively little attention. In this paper we focus on providing data confidentiality for group communication in WMNs. Compared to other network environments, WMNs present new challenges and opportunities in designing such protocols. We propose a new protocol framework, Secure Group Overlay Multicast (SeGrOM), that employs decentralized group membership, promotes localized communication, and leverages the wireless broadcast nature to achieve efficient and secure group communication. We analyze the performance and discuss the security properties of our protocols. We demonstrate through simulations that our protocols provide good performance and incur a significantly smaller overhead than a baseline centralized protocol optimized for WMNs. 相似文献
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Juan Chen Xiaojiang Du Binxing Fang 《Wireless Communications and Mobile Computing》2012,12(14):1302-1312
Anonymous communication is very important for many wireless sensor networks, because it can be used to hide the identity of important nodes, such as the base station and a source node. In sensor networks, anonymous communication includes several important aspects, such as source anonymity, communication relationship anonymity, and base station anonymity. Existing sensor network anonymous schemes either cannot achieve all the anonymities or have large computation, storage, and communication overheads. In this paper, we propose an efficient anonymous communication protocol for sensor networks that can achieve all the anonymities while having small overheads on computation, storage, and communication. We compare our anonymous communication protocol with several existing schemes, and the results show that our protocol provides strong anonymity protection and has low overheads. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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在语音加密通信过程中,接收方需要通过信号同步来实现精确的解密并恢复出语音信号,而现有方法精确度低且运算量大。为了解决端到端语音加密、解密过程中的同步问题,设计了一种新的基于线性调频信号的同步信号结构。该同步信号是基于带宽经过筛选的线性调频信号产生,避免了因为添加同步信号而使带宽扩展的问题。同步信号结构由两种不同长度的线性调频信号组合而成,不同的组合形式又会产生不同的同步效果。这种结构设计大大提高了同步的精确度和减少了同步运算量。理论和实验证明:该方法可以实现对接收信号帧起始位置进行精确地定位;不会展宽和影响语音信号的频谱;可以透过语音编解码器传输;具有一定的抗噪声性能;运算量比原始结构的同步信号大大减少。 相似文献