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1.
刘春蕊  张书奎  贾俊铖  林政宽 《电子学报》2016,44(11):2607-2617
机会网络是一种不需要在源节点和目的节点之间存在完整路径,利用节点移动带来的相遇机会实现网络通信的延迟容忍自组织网络,它以“存储-携带-处理-转发”的模式进行.为实现互不相交簇间的信息传输,本文设计了一种带阈值的簇移动模型CMMT,并提出了一种基于摆渡(Ferry)节点与簇节点协作的路由算法(CBSW).该算法减少了冗余的通信和存储开销,以及在Spray阶段簇节点没有遇到目的节点或摆渡节点,进入Wait阶段携带消息的节点采用直接分发方式只向目的节点传输等问题.仿真实验表明,CBSW算法能够增加传输成功率,减少网络开销和传输延迟.  相似文献   

2.
针对DTN现有的动态分段网络编码(Dynamic Segmented Network Coding,DSNC)路由算法在编码包头部存在冗余字段、ACK反馈阶段存在冗余开销和节点因无序转发编码包而影响数据包端到端时延等问题,提出基于动态分段网络编码的DTN高效路由算法—ERBNC(Efficient Routing Based on dynamic segmented Network Coding).该算法通过采取压缩编码包头部字段、删除冗余的ACK分组、设置编码包的发送优先级等措施以减少网络开销和数据包平均端到端时延.仿真结果表明,与DSNC算法相比,ERBNC算法在网络开销和端到端时延方面的性能均得到改善.  相似文献   

3.
高动态无线自组网路由协议设计   总被引:1,自引:1,他引:0  
王文弢  卿利 《电讯技术》2012,52(5):804-807
针对节点快速移动过程中网络建立时间较长,数据端到端传输时延无法得到可靠保 障,并且由于维护动态网络连接性造成网络开销较大等方面的问题,提出了一种无线自组网 路由协议,通过分簇算法快速将网络分为多个簇,每个簇包括簇首节点、成员节点和簇间网 关节点。该协议能够应用于快速移动节点构成的高动态无线自组织网络中,实现了先应式和 反应式路由算法进行了有机结合,能够在快速变化的拓扑结构中为未知路由提供优化的路由 结果,利用较小的网络开销实现网络快速构建和数据端到端的实时传输。  相似文献   

4.
节点位置的实时变化以及水下长传输时延等特性影响了移动水声异步网络(MUAANs)的时间同步与自定位精度。针对上述问题,该文研究并提出一种自定位和时间同步联合的单向动态预测算法。该算法通过建立时间同步与自定位联合的状态与观测模型,同时预测不同时刻下移动节点的位置信息与时钟差异,实现网络的联合位置跟踪与动态时间同步。与此同时,由于该算法仅采用节点间的单向信息传输即可实现自定位与时间同步,有效解决了由水下长传输时延导致的移动节点间双向信息交互时延差异的问题,提高了网络的自定位与时间同步精度和效率。仿真结果表明,该文所提算法可以高精度地联合预测移动水声异步网络的自定位与时间同步结果,且有效增强了网络的时间同步与自定位时间效率。  相似文献   

5.
为了优化WSN网络的数据传输特性,设计了基于冗余筛选管控评估的移动WSN超宽带稳定传输算法。基于冗余传输调度机制对区域予以初次分割,通过能量评估方式快速达到区域聚类稳定生存效果,结合构建区域节点能量阈值的方法提高聚类冗余效率,以降低超宽带条件下的节点受限概率。采用区域边界控制方式,通过优化骨干节点剩余能量的方式增强骨干节点工作效率,降低因骨干节点而导致的区域传输抖动,确保中继传输节点性能最佳,以降低链路抖动现象。通过骨干节点能力对传输节点予以甄选,从而提升网络链路传输能力,进一步降低抖动现象对传输性能带来的不利影响。仿真实验表明,所提算法具有更低的网络链路累计抖动频次及更好的网络传输带宽。  相似文献   

6.
由于机会网络中节点的缓存空间有限,容易导致数据分组丢失和时延增加。针对部分数据分组已经到达目的节点,但是该类分组仍在网络中其它节点存储、传输问题,提出一种低缓存占用的Epidemic路由算法(RBER)。该算法通过SV运算进行节点缓存清理,从而避免这类冗余数据分组对缓存的占用。理论分析和仿真结果表明,该机制能够降低网络开销、数据分组的发送和缓存占用。  相似文献   

7.
针对基于epidemic机制的机会网络路由算法未能及时感知相遇节点以及在数据分组交换过程中存在冗余的问题,提出了一种采用跨层感知相遇节点思路的机会网络高效低时延路由算法——ERCES(epidemic routing based on cross-layer encountered-node sensing),通过在物理层、MAC层和网络层之间的跨层信息共享与协同,实现相遇节点及时感知,并且采用节点相遇后立即广播新数据分组、收到SV(summary vector)分组后优先发送目的节点为对方的数据分组、动态自适应发送HELLO分组、借助SV删除节点缓存中已到达目的节点的分组等新机制,减少控制和存储开销,降低分组时延。理论分析验证了ERCES算法的有效性,仿真结果表明:与经典的Epidemic Routing算法及其多个改进相比,ERCES算法的控制开销和存储开销分别减少8.2%和2.1%以上,数据分组平均端到端时延至少降低了11.3%。  相似文献   

8.
针对延迟容忍移动传感器网络(Delay Tolerant Mobile Sensor Networks, DTMSN)提出一种基于网络编码的广播传输机制 (Netcoding-based Broadcast Transmission scheme, NBT)。NBT中,基站(Base Station, BS)将原始数据分批进行传输,每个批次包含的原始数据包的数量一定;BS将同一批次数据包以单播方式传输给不同传感器节点时采用的编码向量互不相关,传感器节点之间采用泛洪的机制交换彼此缺少的编码数据包。由于BS对原始数据包进行了编码,因此传感器节点具有相同编码数据包的可能性大大降低,从而减小了节点间的数据相关度,有效降低了广播时延。在随机路点移动模型(Random WayPoint, RWP)下的仿真结果表明,与目前广播时延最小的泛洪机制相比,NBT能够在通信开销基本相同的情况下有效降低广播传输时延。  相似文献   

9.
由于低功耗有损网络(LLN)中无线链路的不稳定性和有损性,外部环境的干扰极易导致网络出现故障,从而严重影响网络性能,而LLN网络中现有路由修复算法存在控制开销冗余和修复时延较大等问题。为此,提出了一种高能效低时延的LLN路由修复算法(EELDR-RPL)。该算法通过采用“零额外控制开销通告链路故障及邻居节点信息”机制,使得链路故障节点的子节点能够及时获知链路故障以及链路故障节点的邻居情况;通过采用“自适应调整节点网络深度值”机制,使得链路故障节点能够快速地重新接入网络;通过采用“链路故障节点子节点自适应切换”机制,能够达到优化网络拓扑的目的。仿真结果表明,与现有路由修复算法相比,EELDR-RPL算法能够有效地降低路由修复时延和减少控制开销。  相似文献   

10.
在交通路灯监控系统中为节省网络节点能耗和降低数据传输时延,提出一种无线传感网链状路由算法(CRASMS)。该算法根据节点和监控区域的信息将监控区域分成若干个簇区域,在每一个簇区域中依次循环选择某个节点为簇头节点,通过簇头节点和传感节点的通信建立簇内星型网络,最终簇头节点接收传感节点数据,采用数据融合算法降低数据冗余,通过簇头节点间的多跳路由将数据传输到Sink节点并将用户端的指令传输到被控节点。仿真结果表明:CRASMS算法保持了PEGASIS算法在节点能耗方面和LEACH算法在传输时延方面的优点,克服了PEGASIS 算法在传输时延方面和LEACH算法在节点能耗方面的不足,将网络平均节点能耗和平均数据传输时延保持在较低水平。在一定的条件下,CRASMS算法比LEACH和PEGASIS算法更优。  相似文献   

11.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

12.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

13.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

14.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

15.
A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.  相似文献   

16.
A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.  相似文献   

17.
Call for Papers     
正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks  相似文献   

18.
正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first  相似文献   

19.
20.
正Journal of Electronics(China)(JE)was founded in 1984,sponsored by the Institute of Electronics,Chinese Academy of Sciences.JE is one of the first English academic journals in China in the field of Electronics and Information technology.The journal was published quarterly since it was launched in 1984 to 2003,then it is published bimonthly till now.During  相似文献   

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