共查询到20条相似文献,搜索用时 140 毫秒
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随着对海洋研究与探索的日益深入,水下传感器网络技术在海洋通信、资源探测、环境监测等领域展现出了巨大的应用潜力.由于海洋介质的特点,水下传感器网络与陆地无线网络有很大的不同.MAC协议作为水下传感器网络的重要组成部分,对该技术的应用发展至关重要的作用.本文概述了MAC协议的设计准则和研究现状,根据MAC协议基于竞争和基于调度的分类进行了不同协议的介绍,并比较了各类协议在效率、吞吐量、功耗等方面的优劣,探讨了MAC协议设计的发展方向. 相似文献
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在无线传感器网络体系结构中,MAC(Medium Access Control)协议是保证网络高效通信的重要协议.无线传感器网络有着与传统无线网络明显不同的性能特点和技术要求.对于很多的 MAC 层协议而言,吞吐量很大程度上受到了物理信道的利用率和协议开销的限制.这里设计了一种基于一对多拓扑的无线传感器Mac层网络协议.最后,还通过NS-2(Network Simulator 2)仿真并比较该协议与现存无线传感器MAC层网络协议的网络性能. 相似文献
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高效节能的无线传感器网络MAC协议 总被引:1,自引:0,他引:1
媒体访问控制协议是保证无线传感器网络高效通信的关键网络协议之一,与传统网络的MAC协议不相同的是,无线传感器网络的MAC协议首要考虑的因素就是节省能量。本文介绍了MAC协议的设计要点以及协议分类,并分析了现有的各种传感器网络MAC协议。并在每一类取一个代表,LPL,S-MAC和L-MAC进行了耗能仿真比较。根据仿真结果,我们得出每个协议在其节能方面都有其特点,所以我们认为不存在一个适应所有传感器网络的MAC协议,应该根据无线传感器网络的应用选其相适应的MAC协议。 相似文献
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无线传感器网络是一种全新的计算模式,是继因特网之后将对21世纪人类生活方式产生重大影响的IT热点技术,媒体介质访问控制(MAC)协议的研究成为无线传感器网络研究中的热点。介绍了无线传感器网络MAC协议的设计性能指标,无线传感器网络中的节能相关问题,然后对现有的无线传感器网络MAC协议按照其实现方法的特点进行了分类,并分析了每个类型中的典型协议的优缺点,最后展望了无线传感器网络MAC协议未来的研究方向。 相似文献
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一种高能效无线传感器网络MAC协议 总被引:1,自引:1,他引:0
介质访问控制(MAC)协议是无线传感器网络研究领域的基础协议和支撑技术.因此,一种能量高效的MAC协议是提高整个无线传感器网络能量效率的基础.针对无线网络中能量储备有限的特点,在分析了现有无线传感器网络节能协议的基础上,提出了一种能量高效的MAC协议.通过动态调整占空比和消除边界节点等方式,提高了无线传感器网络的能量效率,延长了网络的生命周期. 相似文献
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无线传感器网络(Wireless Sensor Network,WSN)一般由部署在监测区域内大量廉价微型传感器节点组成,通过无线通信方式形成一个多跳(mutli hop)的自组织(self organizing)网络系统。MAC层协议设计是无线传感器网络设计中的一个重要研究方面,通过对当前众多MAC协议的研究,提出了一种无线传感器网络MAC层协议的分类方法,通过分析比较典型的MAC层协议,给出了MAC层协议设计的评价标准。 相似文献
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浅海水声信道的快衰落、长延时使水声网络媒介访问控制(MAC)层协议的性能受到了较大的负面影响。为了能更好地将无线传感器网络的MAC协议适用于水声网络,本文着重对Aloha协议和冲突避免多址接入(MACA)协议进行改进分析,借助通信网络仿真工具OPNET,比较两者在吞吐量、时延、能量损耗和分组丢失率4方面的性能结果。仿真结果表明:与Aloha协议相比,MACA协议能更好地提高性能,有利于在水声网络中使用。 相似文献
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Senlin Zhang Liangfang Qian Meiqin Liu Zhen Fan Qunfei Zhang 《Journal of Signal Processing Systems》2017,89(1):3-12
Underwater wireless sensor networks are significantly different from terrestrial wireless sensor networks in that sound is mainly used as the communication medium. The limited bandwidth, long propagation delay and high bit error rate pose great challenges in Media Access Control (MAC) protocol design for underwater wireless sensor networks. In this paper, we propose a Slotted-FAMA based MAC protocol for underwater wireless sensor networks with data train, called SFAMA-DT. It improves the channel utilization by forming a train of data packets of multiple transmission pairs during each round of simultaneously handshakes, which overcomes the multiple RTS attempts problem of Slotted-FAMA in high traffic environments and greatly reduces the relative proportion of time wasted due to the propagation delays of control packets. Our simulations show that the SFAMA-DT is able to achieve much higher throughput than the Slotted-FAMA protocol. 相似文献
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《Selected Areas in Communications, IEEE Journal on》2008,26(9):1754-1766
Interest in underwater acoustic networks has grown rapidly with the desire to monitor the large portion of the world covered by oceans. Fundamental differences between underwater acoustic propagation and terrestrial radio propagation may call for new criteria for the design of networking protocols. In this paper, we focus on some of these fundamental differences, including attenuation and noise, propagation delays, and the dependence of usable bandwidth and transmit power on distance (which has not been extensively considered before in protocol design studies). Furthermore, the relationship between the energy consumptions of acoustic modems in various modes (i.e., transmit, receive, and idle) is different than that of their terrestrial radio counterparts, which also impacts the design of energyefficient protocols. The main contribution of this work is an in-depth analysis of the impacts of these unique relationships. We present insights that are useful in guiding both protocol design and network deployment. We design a class of energyefficient routing protocols for underwater sensor networks based on the insights gained in our analysis. These protocols are tested in a number of relevant network scenarios, and shown to significantly outperform other commonly used routing strategies and to provide near optimal total path energy consumption. Finally, we implement in ns2 a detailed model of the underwater acoustic channel, and study the performance of routing choices when used with a simple MAC protocol and a realistic PHY model, with special regard to such issues as interference and medium access. 相似文献
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MAC protocols for wireless sensor networks: a survey 总被引:25,自引:0,他引:25
Wireless sensor networks are appealing to researchers due to their wide range of application potential in areas such as target detection and tracking, environmental monitoring, industrial process monitoring, and tactical systems. However, low sensing ranges result in dense networks and thus it becomes necessary to achieve an efficient medium-access protocol subject to power constraints. Various medium-access control (MAC) protocols with different objectives have been proposed for wireless sensor networks. In this article, we first outline the sensor network properties that are crucial for the design of MAC layer protocols. Then, we describe several MAC protocols proposed for sensor networks, emphasizing their strengths and weaknesses. Finally, we point out open research issues with regard to MAC layer design. 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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Power management is an important issue in wireless sensor networks (WSNs) because wireless sensor nodes are usually battery powered, and an efficient use of the available battery power becomes an important concern specially for those applications where the system is expected to operate for long durations. This necessity for energy efficient operation of a WSN has prompted the development of new protocols in all layers of the communication stack. Provided that, the radio transceiver is the most power consuming component of a typical sensor node, large gains can be achieved at the link layer where the medium access control (MAC) protocol controls the usage of the radio transceiver unit. MAC protocols for sensor networks differ greatly from typical wireless networks access protocols in many issues. MAC protocols for sensor networks must have built‐in power conservation, mobility management, and failure recovery strategies. Furthermore, sensor MAC protocols should make performance trade‐off between latency and throughput for a reduction in energy consumption to maximize the lifetime of the network. This is in general achieved through duty cycling the radio transceiver. Many MAC protocols with different objectives were proposed for wireless sensor networks in the literature. Most of these protocols take into account the energy efficiency as a main objective. There is much more innovative work should be done at the MAC layer to address the hard unsolved problems. In this paper, we first outline and discuss the specific requirements and design trade‐offs of a typical wireless sensor MAC protocol by describing the properties of WSN that affect the design of MAC layer protocols. Then, a typical collection of wireless sensor MAC protocols presented in the literature are surveyed, classified, and described emphasizing their advantages and disadvantages whenever possible. Finally, we present research directions and identify open issues for future medium access research. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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Due to the characteristics of underwater acoustic channel, such as long propagation delay and low available bandwidth, media access control (MAC) protocol designed for the underwater acoustic sensor network (UWASN) is quite different from that for the terrestrial wireless sensor network. However, for the contention-based MAC protocols, the packet transmission time is long because of the long preamble in real acoustic modems, which increase the packet collisions. And the competition phase lasts for long time when many nodes are competing for the channel to access. For the schedule-based MAC protocols, the delay is too long, especially in a UWASN with low traffic load. In order to resolve these problems, a hybrid reservation-based MAC (HRMAC) protocol is proposed for UWASNs in this paper. In the proposed HRMAC protocol, the nodes reserve the channel by declaring and spectrum spreading technology is used to reduce the collision of the control packets. Many nodes with data packets to be transmitted can reserve the channel simultaneously, and nodes with reserved channel transmit their data in a given order. The performance analysis shows that the proposed HRMAC protocol can improve the channel efficiency greatly. Simulation results also show that the proposed HRMAC protocol achieves better performance, namely higher network throughput, lower packet drop ratio, smaller end-to-end delay, less overhead of control packets and lower energy overhead, compared to existing typical MAC protocols for the UWASNs. 相似文献
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水声传感网因其广阔的应用领域和巨大的应用潜力,近年来已成为通信领域的研究新热点,MAC协议是水声传感网的重要组成部分.概述水声传感网MAC协议的研究现状,指出水声传感网的MAC协议大体可分为基于非竞争的MAC协议和基于竞争的MAC协议,并对不同类别协议的优缺点进行对比分析.针对现有各种协议在吞吐量、开销、信道利用率以及网络的扩展性等方面均存在优势和不足等,从如何更好地克服水声通信中的传播时延长、可用带宽有限、能量消耗大和移动性大等方面,提出更合理更实用的水声通信MAC协议将是该领域未来的重点研究方向. 相似文献