带休眠算法的无线传感器网络MAC协议

由于无线传感器网络中每个传感器节点的能量有限,所以需要有效的MAC协议来保持能量的高效利用。在MAC协议中引入休眠算法是其中一种重要的节能方式。现有的带休眠算法的无线传感器网络MAC协议已有很多种,主要分为2大类:一类是以S-MAC协议为代表的基于休眠/监听排程方案来达到节能目的的MAC协议;另一类是以WiseMAC为代表的基于低功率信道检测方案的MAC协议。对现有的主要几种有代表性的带休眠算法的无线传感器网络MAC协议进行了描述,分析了它们各自的优缺点,并进行了对比和总结。     

无线传感器网络MAC协议休眠机制研究

提高网络的能量有效性是无线传感器网络设计的争的能量有效MAC协议休眠机制的现有研究情况,最后指出了该领域的一些研究方向.     

水下传感器网络MAC协议分析与研究

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.     

水下无线传感器网络MAC协议分析

在水下无线传感器网络中,MAC (Medium Access Control)协议为相互竞争的用户之间公平地分配信道资源.介绍了水声通信的特点以及在此环境下设计MAC协议所面临的主要问题,归纳水下无线传感器网络MAC协议的设计原则和分类方法.通过分析当前典型的各类MAC协议的主要机制,详细比较这些协议的特点、性能差异和...     

CT-TDMA：水下传感器网络高效TDMA协议

针对水下无线传感器网络(UWSN,underwater sensor networks)提出以发送端为中心以连续时间为计量单位的冲突状态模型——局部冲突状态图及其分布式构建算法,并在此基础上设计了基于启发式规则的水下传感器网络TDMA协议(CT-TDMA,continuous time based TDMA)。CT-TDMA利用UWSN中同一接收节点与不同发送节点之间链路时延的差异性,减少在目的端的接收帧之间的空闲时间,从而提高网络流量;基于启发式规则的分配算法,能有效缩短连续时间轴上的时刻分配所花费的时间。模拟实验证明:CT-TDMA与以ST-MAC为代表的按时隙分配的TDMA方案相比,网络流量提高了20%,数据分组的端到端时延降低了18%;与由全局知识所计算出的最优分配策略相比,网络流量达到了80%,端到端时延仅延长了12%。     

基于节点休眠的水下无线传感器网络覆盖保持分簇算法

为有效延长水下无线传感器网络的生命周期、保持网络覆盖率,该文提出一种基于节点休眠的覆盖保持分簇算法。首先计算网络节点的覆盖冗余度,并对覆盖冗余度高的节点执行休眠策略,然后以网络覆盖率及节点能耗均衡性为目标,采用多目标算法进行求解,再利用TOPSIS法从非支配解集中选出较优解,当有节点死亡时,通过唤醒策略保持网络覆盖率。仿真结果表明,与目前较好的网络规划算法相比,该文算法能够更好地降低网络能耗,延长网络生命周期并保持网络对环境的覆盖率。     

无线传感器网络及其MAC层协议

无线传感器网络（WSN）是当今信息领域的一大研究热点，在军事、环境、医疗护理和智能家居等方面有着广阔的应用前景，引起了世界各国的广泛关注。首先介绍了无线传感器网络的相关理论知识，然后对无线传感器网络目前所采用的典型的MAC协议按类型进行了介绍。     

无线传感器网络路由协议中休眠调度算法的研究

在分析无线传感器网络节能要求的基础上对无线传感器网络路由协议中使用的休眠调度算法进行了讨论,内容包括各种休眠调度算法的基本实现方法、考虑因素以及涉及到的关键技术.最后指明休眠调度对传感器网络节能的重要性.     

基于无线传感器网络的MAC协议研究

无线传感器网络是一种应用极为广泛的新兴网络,MAC协议的研究已成为无线传感器网络中的研究热点。本文对几种典型MAC协议进行了分析,通过讨论其优缺点,指出了当前无线传感器网络面临的挑战,展望了进一步的研究方相。     

无线传感器网络MAC协议研究

本文首先从应用需求和业务特性两方面分析了无线传感器网络MAC协议设计面临的挑战.然后,结合现有典型协议,对无线传感器网络MAC协议的研究现状和趋势、节能策略及协议其他特点进行了分析与总结.最后,探讨了无线传感器网络MAC协议的待研究问题.     

一种用于水声传感网的MAC层协议

针对分簇的水声传感网,提出了一种基于时分多址（TDMA）的MAC层协议——Cluster-TDMA。该协议主要由规划阶段和传输阶段组成。规划阶段,首先由网关节点规划能造成簇间干扰的子节点的传输,其次由各簇头节点分别规划本簇内其他子节点的传输;传输阶段,子节点根据规划表周期性地向簇头节点发送数据,这些数据最终汇聚到网关节点。该协议简单有效地解决了引起簇间干扰子结点的传输规划问题。C++仿真实验表明,该协议具有良好的吞吐率和能量效率性能。     

水下无线传感器网络DBR路由协议研究

DBR(Depth Based Routing)协议是水下无线传感器网络中第一个基于深度信息的路由协议。分析了水下无线传感器网络中DBR路由协议特性,详细阐述了DBR协议中的网络拓扑结构、数据转发机制及其存在的一些问题。并简单介绍了目前有关DBR的改进路由协议。     

RPCP‐MAC: Receiver preambling with channel polling MAC protocol for underwater wireless sensor networks

To design a reliable and energy efficient medium access control (MAC) protocol for underwater wireless sensor networks (UWSNs) is an active research area due to its variety of applications. There are many issues associated with underwater acoustic channels including long and variable propagation delay, attenuation, and limited bandwidth which pose significant challenges in the design of MAC protocol. The available sender‐initiated asynchronous preamble‐based MAC protocols for UWSNs are not reliable and energy‐efficient. This is due to the problems caused by transmission of preambles for longer duration and collision of preambles from hidden nodes in sender‐initiated preamble‐based MAC protocols. To resolve these issues, the paper proposed an asynchronous receiver‐initiated preamble‐based MAC protocol named Receiver Preambling with Channel Polling MAC (RPCP‐MAC) protocol for shallow underwater monitoring applications with high data rates. The protocol is proposed to resolve data packet collision and support reliability in an energy‐efficient way without using any transmission schedule. The proposed protocol is based on the following mechanisms. Firstly, receiver preambling mechanism is adopted to reduce idle listening. Secondly, channel polling mechanism is used to determine missing data frame during its sleeping period and to minimize the active time of node and reduces energy wastage. Finally, a back‐off mechanism is applied to resolve collision when preambles are received simultaneously. In addition, performance analysis through Markov chain together with its validation with simulation‐based studies is reported in the paper. Both the analytical and simulation results have demonstrated the reliability achievable with RPCP‐MAC while providing good energy efficiency.     

UW‐MAC: An underwater sensor network MAC protocol

As over 70% of the earth's surface is covered by water, it is desirable to deploy underwater sensor networks (UWSNs) to support oceanic research. UWSNs use acoustic waves and are characterized by long and variable propagation delays, intermittent connectivity, limited bandwidth and low bit rates. Energy savings have always been the primary concern in wireless sensor network protocols; however, there are applications where the latency and throughput are prioritized over energy efficiency and are so significant that the application would not be able to satisfy its requirements without them. Although existing duty‐cycle MAC protocols are power efficient, they introduce significant end‐to‐end delivery latency, provide poor throughput and are not suitable for the challenging environment of a UWSN. In this paper, we utilize CDMA as the underlying multiple access technique, due to its resilience to multi‐path and Doppler's effects prevalent in underwater environments. We propose UW‐MAC, a CDMA‐based power‐controlled medium access protocol that uses both transmitter‐based and receiver‐based CDMA inside a formed cluster, and uses a TDMA schedule to make the cluster heads communicate with the base station. Our MAC algorithm targets the latency and throughput needs in addition to its ability to increase the overall network lifetime. We discuss the design of UW‐MAC, and provide a head‐to‐head comparison with other protocols through extensive simulations focusing on the performance in terms of latency, throughput, and energy consumption. Copyright © 2009 John Wiley & Sons, Ltd.     

Distributed estimation of sensors position in underwater wireless sensor network

In this paper, a localisation method for determining the position of fixed sensor nodes in an underwater wireless sensor network (UWSN) is introduced. In this simple and range-free scheme, the node localisation is achieved by utilising an autonomous underwater vehicle (AUV) that transverses through the network deployment area, and that periodically emits a message block via four directional acoustic beams. A message block contains the actual known AUV position as well as a directional dependent marker that allows a node to identify the respective transmit beam. The beams form a fixed angle with the AUV body. If a node passively receives message blocks, it could calculate the arithmetic mean of the coordinates existing in each messages sequence, to find coordinates at two different time instants via two different successive beams. The node position can be derived from the two computed positions of the AUV. The major advantage of the proposed localisation algorithm is that it is silent, which leads to energy efficiency for sensor nodes. The proposed method does not require any synchronisation among the nodes owing to being silent. Simulation results, using MATLAB, demonstrated that the proposed method had better performance than other similar AUV-based localisation methods in terms of the rates of well-localised sensor nodes and positional root mean square error.     

无线传感器网络协议探究

随着物联网技术的深入发展,无线传感器网络的应用也越来越广泛.然而,无线传感器网络的技术还有待进一步的发展,也促使人们对于无线传感器网络协议的深入探究.本文针对无线传感器网络协议的网络层协议和MAC层协议的分类做了详细的描述和总结,为后续人们进一步研究做好铺垫.     

DRP: An energy‐efficient routing protocol for underwater sensor networks

The features of transmissions in underwater sensor networks (UWSNs) include lower transmission rate, longer delay time, and higher power consumption when compared with terrestrial radio transmissions. The negative effects of transmission collisions deteriorate in such environments. Existing UWSN routing protocols do not consider the transmission collision probability differences resulting from different transmission distances. In this paper, we show that collision probability plays an important role in route selection and propose an energy‐efficient routing protocol (DRP), which considers the distance‐varied collision probability as well as each node's residual energy. Considering these 2 issues, DRP can find a path with high successful transmission rate and high‐residual energy. In fact, DRP can find the path producing the longest network lifetime, which we have confirmed through theoretical analysis. To the best of our knowledge, DRP is the first UWSN routing protocol that uses transmission collision probability as a factor in route selection. Simulation results verify that DRP extends network lifetime, increases network throughput, and reduces end‐to‐end delay when compared with solutions without considering distance‐varied collision probability or residual energy.     

Signaling game approach to improve the MAC protocol in the underwater wireless sensor networks

Underwater sensor networks (UWSNs) are instructed for critical applications like military surveillance and underwater oil spills that conducted in a very massive three‐dimensional (3‐D) space that needs many underwater nodes (UNs) to cover the target area. Those UNs are not easy to recharge and cannot exploit solar power. MAC protocols deployed for UWSN ought to consider the energy efficiency, so as, to extend the network lifetime with total connectivity and significant throughput. Terrestrial MAC protocols could not be used for UWSN due to long and unpredictable propagation delay. Consequently, the development of a new MAC protocol for the harsh environment as underwater is a challenging task. In this study, we focus on the deployment of TDMA in UWSN for this, two schemes entitled TDMA slot sharing (TSS) and free time slots reallocation (FTSR) are proposed. Received data stored in the buffer waiting for processing and forwarding might lead to an unlimited data transfer latency those results in the buffer overflow. Otherwise, free time slots appearing during the communication process resulting from dead nodes increase uselessly sleep time for the rest of the nodes. Both schemes based on signaling game are proposed to overcome those problems, TSS is used to enable the slot sharing between UNs during the communication process to reduce the buffer overflow. FTSR scheme aims to increase the throughput of UNs by allowing the reuse of free time slots. Numerical results conducted in this work show good improvement in the network performance concerning throughput.     

低占空比、低碰撞的异步无线传感器网络MAC协议

提高信道监听质量是降低能量消耗和提高通信效率的有效方法。提出了一种低占空比、低碰撞的PB-MAC(predict-base MAC)协议。通过发送节点精确预测接收节点的唤醒时间,降低占空比;采用基于预测的重建连接机制和数据重传机制,有效地避免碰撞和实现高效重传。OMNet++仿真实验结果表明：在50节点随机网络中,PB-MAC的平均占空比、发送消息耗能和平均碰撞次数分别比RI-MAC少68.60%、24.75%、68.05%,比X-MAC少64.39%、64.05%、70.54%。同时,在网格网络中PB-MAC的性能也优于RI-MAC和X-MAC。