共查询到17条相似文献,搜索用时 140 毫秒
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马荣飞 《计算机工程与设计》2012,33(6):2156-2159
提出了适用于无线视频传感器网络的基于能量感知的跨层交互多路径协作路由技术.该技术首先采用了基于视频传感器节点感知距离的遗传优化算法,预测传输视频数据的能耗和剩余能量,结合无线信道质量和视频编码算法建立一种跨层协同的工作体系,优化节点传输视频数据的能耗、时延和带宽等因素;然后建立应用层、网络层和物理层跨层协同工作体系.仿真实验和数学分析表明,该技术不仅能够较好地满足视频传感器网络应用业务的多样性QoS数据传输性能需求,而且可以充分利用视频传感器网络受限的计算、存储能力和能量等资源. 相似文献
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由于无线多媒体传感器网络链路动态变化、节点移动、带宽和能量受限等特点,传统的分层协议及其局部优化很难保证整个网络性能最优。为实现无线传感器网络中多媒体业务保障服务质量(QoS),提出一种基于业务驱动和自反馈机制的无线多媒体传感器网络跨层优化策略。该策略按照保证QoS等级最高业务服务质量原则,自适应优化网络协议栈各层参数,并将优化后参数反馈给相应网络协议层,实现保证QoS的网络资源优化,仿真结果表明,该方法在综合物理层误码率和链路层数据帧丢失率的情况下,与传统网络分层协义相比,提高多媒体信息传输质量方面有一定优越性。 相似文献
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无线传感器网络是一类由大量位置相对固定的节点所组成的无线通信网络,其节点能量、计算和通信能力都非常有限,因此,传统网络的层次设计和网络协议都难以应用到无线传感器网络中。为解决这些问题,该文在传统网络层次设计思想的基础上,提出了适用于无线传感器网络节点的跨层网络模型,基于OPNET网络仿真工具实现了节点的跨层网络模型设计,在此基础上实现了无线传感器网络中路由选择和数据汇聚等典型应用的仿真。结果表明,新的跨层网络模型能够很好地描述节点各个层次的功能,便于网络协议的综合设计和集中优化。 相似文献
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无线网络的差错控制策略及其性能分析 总被引:1,自引:1,他引:0
研究网络数据优化传输性能,针对无线传感器网络动态的信道特性、拓扑和带宽有限等特点,要保证输出性能和效率,对网络差错应选择严格控制策略.为了提高无线传感器网络通信的可靠性,提出一种适用于无线传感器网络多媒体数据传输的自适应差错控制策略.策略采用跨层设计的方法,根据链路层数据帧所属应用层视频帧的类型及其发送节点和下一跳接收节点之间的通信距离特性,自适应地选择当前最优的差错控制技术.数学分析表明,策略充分利用无线传感器网络的能量和带宽资源,有效地提高了数据通信的传输效率和可靠性. 相似文献
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无线传感器网络的通信能量有效性的研究 总被引:2,自引:0,他引:2
无线传感器节点通常依靠电池供能,为了满足无线传感器网络的往往长达数年的生命周期要求,应当努力提高其能量有效性,特别是消耗大部分能量的通信模块的能量有效性.首先系统讨论了无线传感器网络的通信的能量有效性的研究现状,然后基于传感器节点的通信模块的功耗特性,运用应用驱动和跨层优化的方法,设计了一种无线传感器网络通信架构--ADCOCA (Application-Driven and Cross-layer Optimized Communication Architecture).理论分析表明,ADCOCA改善了无线传感器网络通信的能量有效性,延长了网络的生命周期,推动了无线传感器网络应用的普及. 相似文献
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多媒体传感器网络中基于两跳簇结构的图像传输方案 总被引:3,自引:0,他引:3
与传统无线传感器网络节点能量绝大部分消耗在无线收发上不同,无线多媒体传感器网络中数据处理与传输能耗具有“均匀“分布的特点.通过分析表明,传统无线传感器网络簇结构下的数据传输策略并不适合于无线多媒体传感器网络.因此提出了一种基于两跳簇结构的图像传输方案,通过增加中继节点负责图像的压缩编码和转发,在减小相机节点图像传输能耗的同时,大大缓解了相机节点和簇头的图像处理能耗压力.仿真结果表明,该图像传输方案极大的延长了网络的生命周期,非常适合于能量有限的无线多媒体传感器网络. 相似文献
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多媒体传感器网络作为一种多媒体信息获取和处理方式,已在军事、民用及商业领域中显示出广阔的应用前景.信道接入协议能否高效地使用无线信道是保证无线多媒体传感器网络通信的最关键的因素之一.分析支持多媒体业务传输的无线传感器网络信道接入协议的要求,提出适于多媒体传感器网络提供区分服务的信道接入协议--DSMAC(different service medium access control),对实时业务与非实时业务实现了区分服务,在信道接入帧内的随机竞争期实现突发业务及时接入,支持突发多媒体业务实时传输,并提出了多信道簇间传输方式,避免了隐终端冲突.最后,对协议的服务区分、实时性、吞吐量以及能量有效性等性能进行了仿真实验,验证了其优良性能. 相似文献
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Jenq-Neng Hwang 《Multimedia Systems》2011,17(4):251-285
Thanks to the explosive creation of multimedia contents, the pervasive adoption of multimedia coding standards and the ubiquitous
access of multimedia services, multimedia networking is everywhere in our daily lives. Unfortunately, the existing best effort
IP network infrastructure, originally designed with little real-time QoS requirement, has started to suffer from performance
degradation on emerging multimedia networking applications. This inadequacy problem is further deepened by the prevalence
of last/first-mile wireless networking, such as Wi-Fi, mobile WiMAX, and many wireless sensors and ad-hoc networks. This can
be evidenced by more and more fragmentation of application-driven IP-based networks, such as for power grid distribution,
networked security surveillance, intelligent transportation communication, and many other sensor networks. To overcome the
QoS challenges, the next generation wireless IP networks have to be architected in a top-down manner, i.e., application-driven
layered protocol design. More specifically, based on the application media data, compression schemes are applied, the subsequent
Network, MAC- and PHY-layered protocols need to be accordingly or jointly enhanced to reach the optimal performance. This
is the fundamental concept behind the design of Wireless MediaNets. In this survey paper, I will address the QoS challenges
specifically encountered in video over heterogeneous wireless broadband networks and address several application-driven Wireless
MediaNet solutions based on effective cross-layer integration of APP and MAC/PHY layers. More specifically, the congestion
control for achieving airtime fairness of video streaming to maximize the link adaptation performance of Wi-Fi, the minimum
latency event-driven data exchange for distributed wireless ad-hoc sensor networks, and the opportunistic multicast of scalable
video live streaming over mobile WiMAX. 相似文献
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A variety of data forwarding schemes have been proposed for wireless multimedia sensor networks where energy awareness and reliability are essential design issues. This paper proposes a data forwarding mechanism based on sensor device constraints in wireless multimedia sensor networks. A dynamic path cost function is defined considering the constraints and characteristics of wireless multimedia sensor networks. The cost function is applied to ZigBee mesh routing, and the performance of the proposed method is evaluated using a QualNet network simulator. 相似文献
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对于无线传感器网络而言,可靠的数据收集是推进其大规模应用的关键,本文引入了移动传感器网络解决静态传感网络中的通信中断问题.针对移动传感器网络的数据收集,提出了数据收集的分类,分析了移动节点不同移动模式对网络数据收集的影响,比较了移动节点受控移动路径对比固定移动模式的优势,最后介绍了典型的移动节点受控移动的路径规划算法. 相似文献
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Chungui Liu Yantai Shu Lianfang Zhang Zenghua Zhao Xiang-Yang Li 《Pervasive and Mobile Computing》2009,5(1):19-36
A significant issue in Mesh networks is to support multimedia transmissions while providing Quality of Service (QoS) guarantees to mobile users. For real-time multimedia streaming, unstable throughput or insufficient bandwidth will incur unexpected delay or jitter, and it remains difficult to provide comprehensive service guarantees for a wireless mesh environment. In this paper, we target the problem of providing multimedia QoS in wireless mesh networks. We design and implement a campus test-bed for supporting multimedia traffic in mobile wireless mesh networks, and investigate in detail some possible improvements on a number of layers to enable multimedia transmission over wireless networks with QoS support. We first study a number of improvements of some existing routing protocols to support multimedia transmissions. Some new admission control and rate control mechanisms are studied and their performance gains are verified in our experiments. In our new cross-layer adaptive rate control (CLARC) mechanism, we adaptively change the video encoder’s output bit rate based on the available network bandwidth to improve the quality of the received video. We also design a mobile gateway protocol to connect the MANET to Internet and a wireless LAN management protocol to automatically manage WLAN to provide some QoS. 相似文献