一种用于水声通信网的多址接入协议

由于传输介质的不同，使得水声通信具有一些有别于电磁波通信的特点。本文针对水声信号传播时延长带来的效率低的问题，为水下环境中的通信网提出了一种新型的冲突避免多址接入协议，该协议通过减少不必要RTS／CTS握手次数，降低了这种预约形式所造成的资源浪费，提高了网络效率。仿真结果显示，该协议在水声环境下，能获得较好的网络性能。     

一种能量感知的Ad Hoc网络路由协议

Ad Hoc网络中的节点是由电池供电,整个网络是一个能量受限系统,如何节省节点的能量,尽可能延长网络的可操控时间逐渐成为衡量路由协议性能的重要指标.基于移动节点能量的不同级别,采取不同的转发策略,提出了一种基于能量感知的Ad Hoc网络路由协议--EARP.并与AODV协议进行了性能比较,仿真结果显示,EARP具有较低的能耗,较长的网络存活时间.     

一种基于能量优化的无线传感网络自适应组织结构和协议

本文提出了一种新的无线微传感器网络协议和组织结构ALEP。与传统的无线微传感器网络协议相比，ALEP更加充分地考虑到实际应用，将一种高效能量控制算法引入组网协议，提高了网络的能量利用率，显著延长了无线网络的生命周期，增强了网络的健壮性。通过对ALEP协议进行OPNET仿真，结果显示该协议与传统模式的无线微传感器网络协议相比，在传送相同的数据量的条件下有更高效的能量特性和信息传输特性。     

基于空间唤醒的水声传感器网络节能路由协议

针对水声传感器网络高能耗的特点,该文提出了基于空间唤醒的节能路由协议ERBSW (Energy-efficient Routing protocol Based on Spatial Wakeup),该协议将3维网络空间划分为唤醒层和睡眠层,每个节点根据当前的深度信息,动态地决定其处于唤醒或睡眠状态。另外,ERBSW通过定期地广播Hello包来建立唤醒邻节点集合,使得数据包由较高的唤醒层节点向较低的唤醒层节点传递,从而避免了冗余节点因空闲侦听以及不必要的数据接收所产生的能量浪费。仿真结果表明,在不同网络密度条件下,该协议相比VBF(Vector-Based Forwarding)能耗节省了约16%~48%。     

水声传感器网络MAC协议UW-CSMA/CA的NAV优化

水声传感器网络UW-CSMA/CA协议依据源节点与目的节点间最大传播延时确定NAV,这将导致发生网络延时冗余问题,从而降低网络吞吐量。基于此协议,提出了一种根据节点实际距离计算NAV的AN-MAC协议。该协议根据节点间的实际传输距离计算出传播延时并存储在控制帧中,将节点间实际传播延时替换最大延时来计算NAV,可以有效减少网络冗余延时。为了提高仿真结果的有效性,在NS-Miracle仿真器中将Bellhop和世界海洋仿真系统WOSS相结合,对2种协议进行仿真和比较。结果表明,AN-MAC协议较UW-CSMA/CA协议在吞吐量和传输延时方面均有改善。     

水声通信网综述

近年来,由于水下通信技术的发展和应用需求,国内外对水声通信网络进行了大量的研究工作,并且在方案验证、模拟仿真的基础上,开始了水声网络的海上实验.本文从水声通信网的发展过程和特点出发,系统介绍了水声通信网的体系结构和关键技术,并且详细介绍了各层的研究内容和研究现状,最后对水声通信网今后的研究方向和应用前景进行了展望.     

一种用于格型拓扑的水声传感器网络TDMA协议

由于海洋信道恶劣的传输条件,使设计可靠且有效的水声传感器网络MAC协议面临极大的挑战。该文针对六角格型网络的结构特点提出了G-TDMA协议,该协议通过对时隙的空间复用,提高了信道资源的利用率;并且在数据帧的发送过程中完成网络节点间的同步,从而降低同步开销;同时根据水声信道的高传输延时和起伏特性,加入了保护时间以避免数据冲突。仿真结果表明,在水声信道条件下该协议可有效地改善网络性能。     

一种能量感知无线传感器网络可靠协议研究

针对无线传感器网络协议中可靠性及能量有效性,提出能量感知的无线传感器网络可靠路由EARRP.EARRP通过本地节点选择、路径预留和路径延迟广播来减少由于路径不可达带来的重传,进而提供一个可依赖的传输环境.仿真实验表明EARRP优于在汇聚节点和感应节点之间建立有效路径的传统的方法可以有效利用节点的剩余能量和有限存储资源.同时可以均匀的分配传输路径,进而实现节能目的.     

一种用于水声网络的改进的MAC层协议

减少数据包碰撞,节省能量,保持收发数据的同步性是水声网络MAC层协议设计的关键策略.本文在一种已有的UWAN-MAC协议的基础上展开研究,提出了一种改进的UWAN-MAC协议,该协议在不影响节点同步的前提下,通过优化节点的收发数据包机制,可以获得更低的碰撞率和更高的节能效果.最后通过仿真对原协议和修改后的协议进行了比较和分析.     

三维水声传感器网络能量高效路由算法

针对三维水声传感器网络,在研究水声信道能耗特性的基础上,设计了一种能量高效的路由算法Hybrid LEACH。它基于经典的LEACH算法,而在簇间传输中使用一种树状路由取代簇头与汇聚节点直接通信,减少了簇头节点的能耗,达到延长网络生存时间的目的。仿真结果显示,Hybrid LEACH算法在网络规模较大的情况下可以有效延长网络生存时间。     

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。     

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.     

基于OPNET的水声通信网MAC层协议的研究

AC（Multiple Access）协议是水声通信网络的重要研究内容,利用OPNET网络仿真软件对ALOHA协议和MACAW协议下水声通信网络的性能进行仿真研究,分析比较这两种协议在不同业务量下的网络性能。仿真结果表明,在水声通信网络中,MACAW协议的性能优于ALOHA,但两者均可应用于低数据业务量网络中。     

一种有效的水声通信网络中用于半双工信道的ARQ协议

自动重传请求(ARQ)在保证通信网络可靠传输中起着关键的作用。但是，在水声通信网络中，由于水声信道的半双工以及信道的长传播时延特性，使得水声通信网络的吞叶性能受到极大的制约。本文针对水声信道长传播时延这一特点，利用扩频通信技术，将单个信道分成两个子信道；一个用于前向信道(从发送方到接收方)，另一个用于反向信道(从接收方到发送方)，从而使得对每个分组数据的响应时间大大缩短，提出了一种有效的适合于半双工特性的ARQ协议。理论分析和仿真结果表明，相对于传统的SW ARQ协议而言，该协议在水声信道下具有更优的吞吐性能。     

一种基于有限状态机的新型水声网络多址接入协议的实现

本文首先提出了一种新型的水声通信网络的多址接入(UAMA)协议.该协议针对水声信道传播时延长的特点,利用扩频码进行多信道预约;通过适当的控制方法,采用与传统的握手协议不同的机制,当发送方发送request_to_send(RTS)后,在选择的业务信道上立刻传输数据,而不必等收到clear_to_send(CTS)后再传输数据,在时间和空间上大大地提高了信道的利用率,因此极大地提高了网络的吞吐量.通过使用OPNET Modeler/Radio仿真器对UAMA协议进行了基于有限状态机(FSM)的建模和设计.仿真结果表明该协议能在水声环境下取得优良的吞吐性能和较低的分组传输时延.     

Routing design avoiding energy holes in underwater acoustic sensor networks

Interest in underwater acoustic sensor networks (UW‐ASNs) has rapidly increased with the desire to control the large portion of the world covered by oceans. Energy efficiency is one of the major concerns in UW‐ASNs due to the limited energy budget of the underwater sensor nodes. In this paper, we tackle the problem of energy holes in UW‐ASNs while taking into consideration the unique characteristics of the underwater channel. We prove that we can evenly distribute the transmission load among sensor nodes provided that sensors adjust their communication range when they send or forward the periodically generated data. In particular, we propose a balanced routing strategy along with the associated deployment pattern that meticulously determines the load weight for each possible next hop that leads to fair energy consumption among all underwater sensors. Consequently, the energy holes problem is overcome, and hence, the network lifetime is improved. To the best of our knowledge, this is the first work that addresses the energy hole problem in UW‐ASNs. Copyright © 2016 John Wiley & Sons, Ltd.     

一种用于水声通信网的TDMA方案

由于海洋中恶劣的传输条件，设计高可靠性、高吞吐量的水下通信网是一项具有很强的挑战性的工作。本文提出了一种适合水下环境中通信网使用的TDMA方案，该方案通过TDMA数据帧的交错布置减少信道的闲置时间，提高网络效率。仿真实验结果表明，该TDMA方案具有较高的网络性能。     

LRP: Link quality‐aware queue‐based spectral clustering routing protocol for underwater acoustic sensor networks

Recently, underwater acoustic sensor networks (UASNs) have been considered as a promising approach for monitoring and exploring the oceans in lieu of traditional underwater wireline instruments. As a result, a broad range of applications exists ranging from oil industry to aquaculture and includes oceanographic data collection, disaster prevention, offshore exploration, assisted navigation, tactical surveillance, and pollution monitoring. However, the unique characteristics of underwater acoustic communication channels, such as high bit error rate, limited bandwidth, and variable delay, lead to a large number of packet drops, low throughput, and significant waste of energy because of packets retransmission in these applications. Hence, designing an efficient and reliable data communication protocol between sensor nodes and the sink is crucial for successful data transmission in underwater applications. Accordingly, this paper is intended to introduce a novel nature‐inspired evolutionary link quality‐aware queue‐based spectral clustering routing protocol for UASN‐based underwater applications. Because of its distributed nature, link quality‐aware queue‐based spectral clustering routing protocol successfully distributes network data traffic load evenly in harsh underwater environments and avoids hotspot problems that occur near the sink. In addition, because of its double check mechanism for signal to noise ratio and Euclidean distance, it adopts opportunistically and provides reliable dynamic cluster‐based routing architecture in the entire network. To sum up, the proposed approach successfully finds the best forwarding relay node for data transmission and avoids path loops and packet losses in both sparse and densely deployed UASNs. Our experimental results obtained in a set of extensive simulation studies verify that the proposed protocol performs better than the existing routing protocols in terms of data delivery ratio, overall network throughput, end‐to‐end delay, and energy efficiency.     

RIM-MAC：一种适用于水下传感网接收者发起的多会话MAC协议

声通信是水下传感网的主要通信方式之一,但是它具有长延迟和低带宽的特点,这是水下传感网MAC（media access control）协议研究面临的主要挑战。为提高网络吞吐量,提出了一种接收者发起的多会话MAC协议（RIM-MAC）。它利用接收者发起会话,通过一次会话的4次握手完成所有邻居数据分组的传输,有效地减少握手次数。同时利用侦听到的本地信息（邻居延迟图和邻居的传输调度）避免信道冲突并发起多个会话,这解决了长传播延迟带来的信道利用率低的问题。RIM-MAC通过增强节点间并行传输的能力,在接收者和发送者两端提高时空复用率,与经典水下MAC协议比,网络吞吐量提高了至少36%。除此之外,基于自适应数据轮询策略提出了一种网络负载公平算法（FTA）,它保证了网络中竞争节点间的信道访问的公平性。仿真实验表明,在长传播延迟的场景下,RIM-MAC取得了比典型的水下传感网MAC协议更好的吞吐量性能。     

An energy‐efficient asynchronous wake‐up scheme for underwater acoustic sensor networks

In addition to the requirements of the terrestrial sensor network where performance metrics such as throughput and packet delivery delay are often emphasized, energy efficiency becomes an even more significant and challenging issue in underwater acoustic sensor networks, especially when long‐term deployment is required. In this paper, we tackle the problem of energy conservation in underwater acoustic sensor networks for long‐term marine monitoring applications. We propose an asynchronous wake‐up scheme based on combinatorial designs to minimize the working duty cycle of sensor nodes. We prove that network connectivity can be properly maintained using such a design even with a reduced duty cycle. We study the utilization ratio of the sink node and the scalability of the network using multiple sink nodes. Simulation results show that the proposed asynchronous wake‐up scheme can effectively reduce the energy consumption for idle listening and can outperform other cyclic difference set‐based wake‐up schemes. More significantly, high performance is achieved without sacrificing network connectivity. Copyright © 2015 John Wiley & Sons, Ltd.