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在网络交换设备中,如何克服可变无线传输环境对其实时通信产生的严重影响,是一个很值得研究的课题。针对无线传输链路速率的实时变化,在深入理解和研究信令处理、策略控制以及业务数据传输的基础上,设计并实现了一种基于可变无线信道传输的网络交换设备。试验结果表明,设备性能稳定可靠,不仅可以提高复杂环境下通信链路的利用率,而且可以保证高优先级业务的可靠实时传输。 相似文献
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通常来讲无线传感器网络的节能与可靠性是矛盾的,节能与可靠性措施很难统一。该文明确了节能可靠传输面临的主要问题,分析了相关解决策略,总结了无线传感器网络中数据节能可靠传输的方案,说明了无线传感器网络应用场景对传输策略选择的影响,并进一步介绍了三种基于IEEE 802.15.4的网络标准。 相似文献
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基于AODV且考虑延时能量节省的路由协议 总被引:1,自引:1,他引:0
重点研究基于节能要求兼低延时效应的AODV路由协议的改进。节能以延长无线传感器网络的工作时间,降低延时效应来保证数据传输的实时性,这是评价一个无线传感器网络的两个重要指标。在总结国内外研究成果的基础上,提出了更适用于低速运动的Ad Hoc网络的低延时节能的路由改进策略,包括在低于能量阈值时的动态功率调整、能量意识的路由选择、广播控制、被动路由更新和CMMBCR的引入。节能策略更是引入了位置信息和网络平均能量的概念,而且更适用于项目的实际情况(低速运动网络)。在用NS-2工具对该低延时节能策略进行仿真测试后,得出在最佳情况下网络传输延时和网路寿命两项指标都能得到大幅度的改进。 相似文献
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在无线传感器网络中,由于传感器节点的能源十分有限,节能是设计的首要因素。然而,无线传感器网络的多业务在现实生活应用中对QoS(服务质量)都有不同的需求,这就使得WSN网络的QoS研究成为了专家学者们的主要研究方向。在WSN网络拓扑结构和业务类型的研究基础上,使用网络模拟器(Network Simulator Version 2,NS2)来搭建基于多业务共存的星型以及对等结构两种WSN网络仿真平台,建立多种业务流量模型,实现以无线传感器网络协议、流量模型、拓扑为基础的功能模块化设计;并对无线传感器网络关键性能进行了仿真模拟,实现延时、吞吐量、能耗等关键性能的分析。 相似文献
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在无线传感器网络实际应用中,组播正在发挥着越来越重要的作用.但由于能量等多方面的因素,使得为无线传感器网络设计一个有效的组播路由是非常困难的.针对无线传感器网络中节点的能量限制,通过寻求节点间最短路径,提出一种能量有效的链路可靠组播路由协议(RLMR).该协议充分考虑到网络中节点的能耗因素和两节点间的链路可靠性等,通过对这两个因素的综合考虑,让能量较多并且以发送节点更靠近的节点承担更多传输任务的方式,为数据流优化路由选择,均衡无线传感器网络节点的能量消耗,以延长网络的生存时间.仿真结果证明了RLMR的有效性和可靠性. 相似文献
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Study of an adaptive frame size predictor to enhance energy conservation in wireless sensor networks 总被引:3,自引:0,他引:3
Technological advances in low-power digital signal processors, radio frequency (RF) circuits, and micromechanical systems (MEMS) have led to the emergence of wirelessly interconnected sensor nodes. The new technological possibilities emerge when a large number of tiny intelligent wireless sensor nodes are combined. The sensor nodes are typically battery operated and, therefore, energy constrained. Hence, energy conservation is one of the foremost priorities in design of wireless sensor networks (WSNs) protocols. Limited power resources and bursty nature of the wireless channel are the biggest challenges in WSNs. Link adaptation techniques improve the link quality by adjusting medium access control (MAC) parameters such as frame size, data rate, and sleep time, thereby improving energy efficiency. In This work, our study emphasizes optimizing WSNs by building a reliable and adaptive MAC without compromising fairness and performance. Here, we present link adaptation techniques at MAC layer to enhance energy efficiency of the sensor nodes. The proposed MAC uses a variable frame size instead of a fixed frame size for transmitting data. In order to get accurate estimations, as well as reducing the computation complexity, we utilize the extended Kalman filter to predict the optimal frame size for improving energy efficiency and goodput, while minimizing the sensor memory requirement. Next, we designed and verified different network models to evaluate and analyze the proposed link adaptation schemes. The correctness of the proposed theoretical models have been verified by conducting extensive simulations. We also prototype the proposed scheme with the MAC protocol on Berkeley Motes. Both prototype and simulation results show that the proposed algorithms improve the energy efficiency by up to 15%. 相似文献
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设计了一种基于GPRS的土壤温湿度实时采集系统,给出了一种基于无线传感器网络的环境监测方案。无线传感器网络是由大量随机分布的传感器节点,通过无线通信技术自组织构成的网络,传感器节点具有数据采集处理、无线通信和自动组网能力。文中利用Telosb节点平台设计了传感器节点的硬件结构,并在TinyOS操作系统的基础上,完成了节点的软件设计。该系统可以对目标监测区内多点的温湿度进行实时采集,实现单跳和多跳的数据传输,同时利用GPRS进行高效可靠的远程传输,实现长期动态监测。 相似文献
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提高无线传感网络的传输效率、节约整个网络的能量消耗是我们研究无线传感网络的重要内容。通常都是通过改变网络的拓扑结构来实现效率的提高,本文给出了一种新的思路去节约能耗。本文讨论了权重与与无线传感网传输效率的关系,将有权的无线传感网络链路上的权值进行随机的分配,我们发现将权重随机分配后网络的传输效率得到了提高并且随着权重分布概率的增大网络的传输效率不断增大。这为我们研究权重对无线传感网络的影响提供了基础。 相似文献
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Mohammed Al‐Hubaishi Celal eken Ali Al‐Shaikhli 《International Journal of Communication Systems》2019,32(17)
Energy consumption is one of the most important design constraints when building a wireless sensor and actuator network since each device in the network has a limited battery capacity, and prolonging the lifetime of the network depends on saving energy. Overcoming this challenge requires a smart and reconfigurable network energy management strategy. The Software‐Defined Networking (SDN) paradigm aims at building a flexible and dynamic network structure, especially in wireless sensor networks. In this study, we propose an SDN‐enabled wireless sensor and actuator network architecture that has a new routing discovery mechanism. To build a flexible and energy‐efficient network structure, a new routing decision approach that uses a fuzzy‐based Dijkstra's algorithm is developed in the study. The proposed architecture can change the existing path during data transmission, which is the key property of our model and is achieved through the adoption of the SDN approach. All the components and algorithms of the proposed system are modeled and simulated using the Riverbed Modeler software for more realistic performance evaluation. The results indicate that the proposed SDN‐enabled structure with fuzzy‐based Dijkstra's algorithm outperforms the one using the regular Dijkstra's and the ZigBee‐based counterpart, in terms of the energy consumption ratio, and the proposed architecture can provide an effective cluster routing while prolonging the network lifetime. 相似文献
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To satisfy the needs of modern precision agriculture, a Precision Agriculture Sensing System (PASS) is designed, which is based on wireless multimedia sensor network. Both hardware and software of PASS are tailored for sensing in wide farmland without human supervision. A dedicated single-chip sensor node platform is designed specially for wireless multi-media sensor network. To guarantee the bulky data transmission, a bitmap index reliable data transmission mechanism is proposed. And a battery-array switching system is design to power the sensor node to elongate the lifetime. The effectiveness and performance of PASS have been evaluated through comprehensive experiments and large-scale real-life deployment. 相似文献