共查询到19条相似文献,搜索用时 632 毫秒
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提出一种网络编码感知机会路由算法,将COPE协议中的机会监听和网络编码技术引入现有的机会路由机制,采用新的路由度量即LQM(链路质量度量)标准来选择备选转发节点集,在确保选择路径的编码机会的同时也在一定程度上保证了链路质量。仿真结果表明,此方法能提高网络的整体吞吐量,增加编码机会,降低平均端到端的时延。 相似文献
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设计能够适应高移动环境下的空基自组网路由协议是目前研究的重点方向。提出了基于负载均衡的优化路由协议,该协议在获得位置信息的前提下,首先预测出通信链路的有效时间,然后在满足数据的时延、带宽以及链路有效性等多约束条件下,路由协议以均衡节点负载为优化目标,使得网络节点都能合理承担数据传输任务。仿真结果表明,设计的路由协议能够保证网络节点合理分担传输任务,充分利用链路资源,提高网络的吞吐量。 相似文献
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无线ad-hoc网络部署在非人为控制的外部环境中,采用电池供电.在这种应用环境中,如何通过合理的路由协议设计降低能量开销、提高网络的生存时间是近年来研究的热点.文章提出一种结合链路质量与能效的跨层路由协议.在路由建立阶段综合考虑链路质量、发送数据包的能耗和节点剩余能量来建立路由.通过在路由维护阶段对链路质量和节点剩余能量进行检测,预测路由中断的发生,并进行本地修复.通过在IEEE 802.15.4 Matlab模拟器下进行仿真,验证了该协议能够有效地提高网络的生存时间、数据投递率及AODV协议的性能和稳定性. 相似文献
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Xiang Yang Weiping Wang Mingming Lu Jianxin Wang Xi Zhang 《Wireless Communications and Mobile Computing》2016,16(14):1922-1942
Because of the broadcast and overhearing capability of wireless networks, network coding can greatly improve throughput in wireless networks. However, our investigation of existing inter‐session network coding protocols found that the short‐term unfairness that existed in 802.11‐based medium access control (MAC) protocols actually decreases the coding opportunity, which in turn compromises the throughput gain of network coding. To alleviate the negative impact of this unfairness, we propose a coding‐aware cross‐layer heuristic approach to optimize the coordination of network coding and MAC layer protocol, named FairCoding, which can significantly increase coding opportunities for inter‐session network coding through a fair short‐term traffic allocation for different coding flows. Experiment evaluation shows that the proposed mechanism can bring more coding opportunities and improve the total throughput of wireless mesh networks by up to 20%, compared with the coding mechanism, without considering the negative impact of the short‐term unfairness. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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针对无线ad hoc网络中协作造成的中继效率低以及不同QoS需求难以满足等问题,提出了一种联合网络编码和空时编码的协作MAC协议(NSTCMAC)。NSTCMAC将网络编码与空时编码技术相结合,设计出区分业务类型的协作MAC协议传输机制,以满足不同业务类型的QoS需求;进一步通过马尔科夫链模型分析了区分业务类型的协作机制及性能。仿真结果表明,相比传统的DCF、COOPMAC以及CD-MAC协议,NSTCMAC协议能更好地保证不同的QoS需求,并能有效地解决协作造成的中继效率低的问题。 相似文献
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The existing wireless cooperative MAC protocols rarely consider the impact of channel condition and node energy consumption.To this issue,a new wireless cooperative MAC protocol was proposed,which used the random linear network coding,and introduced a mechanism of request relay frame to solve the hidden terminal problem.Specifically,the proposed method adaptively adjusted the node rate according to RSSI,and determined the relay node based on the requirements of cooperative transmission.The simulation results show that the network performance can be improved through deploying the proposed protocol. 相似文献
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Angelos Antonopoulos Christos Verikoukis Charalabos Skianis Ozgur B. Akan 《Ad hoc Networks》2013,11(1):190-200
In this paper we introduce a network coding-aided energy efficient Medium Access Control (MAC) protocol that coordinates the transmissions among a set of relay nodes which act as helpers in cooperative Automatic Repeat reQuest-based (ARQ-based) wireless networks. Applying network coding techniques, we achieve to increase the energy efficiency of the network without compromising the system performance in terms of Quality of Service. Our proposed solution is evaluated by both analytical and simulation results. 相似文献
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Sagduyu Y.E. Ephremides A. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2007,53(10):3697-3713
This paper addresses network coding in wireless networks in conjunction with medium access control (MAC). It is known that coding over wired networks enables connections with rates that cannot be achieved by routing. However, the properties of wireless networks (e.g., omnidirectional transmissions, destructive interference, single transceiver per node, finite energy) modify the formulation of time-varying network coding in a way that reflects strong interactions with underlying MAC protocols and deviates from the classical approach used in wired network coding. To perform network coding over conflict-free transmission schedules, predetermined network realizations are separately activated by a time-division mechanism and the content of network flows is derived through network coding to optimize performance measures such as achievable throughput and energy costs. A systematic method is presented to construct linear wireless network codes and interactions with MAC schedules are discussed under wireless assumptions. Network coding is also extended to operate with arbitrary (random or scheduled access based) MAC protocols. Alternatively, conflict-free transmission schedules are jointly constructed with network codes by decomposing wireless networks into subtrees and employing graph coloring on simplified subtree graphs. Finally, network coding and plain routing are compared in terms of throughput, energy and delay performance under different MAC solutions. 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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在无线传感网( WSN)体系结构中,介质访问控制( MAC)协议负责调配网络中节点的信道接入,具有保障网络高效通信的重要作用。混合类MAC 协议综合了竞争类MAC 协议以及调度类MAC协议的特点,在融合两种机制的优点的同时克服其缺点,为无线信道资源的分配提供了更加灵活和全面的策略。首先概述了无线传感网MAC协议设计要点及分类,然后重点分析了无线传感网中经典的混合类MAC协议及国内外前沿的研究进展,并进一步归纳对比了各协议运行机制、性能及不足,得出混合类MAC协议的应用相关性及差异性的结论,最后总结了无线传感网混合类MAC协议研究现状并指出了未来的研究重点,以期为相关领域的研究人员提供参考。 相似文献
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Remote locations coverage analysis with wireless mesh networks based on IEEE 802.16 Standard 总被引:1,自引:0,他引:1
This article analyzes the wireless coverage problem of remote regions with low user density and propagation problems due to irregular terrain and high tree density. The use of a wireless mesh network is proposed as a solution where user data is transmitted directly to a base station when it is possible or relayed through other nodes in a multi-hop manner when there is not a direct link. The mesh topology uses short links with higher capacity instead of long links with low capacity. We analyze radio propagation and MAC protocols, including random sources, queues, and packet delays. The article is based on the coverage of a realistic rural region near Medellin, a mid size city in Colombia, and it shows that a wireless mesh network is an alternative to a typical cell based solution. It includes propagation analysis and MAC protocol behavior, so it is not limited to a radio coverage problem but also traffic, scheduling, and routing analysis 相似文献