适用于水下物联网的混合地理路由协议设计

该文针对水下物联网(IoUT)数据传输问题设计了一种混合地理路由协议。海洋环境的复杂性严重地限制了IoUT水下物联网节点间的数据传输性能,因此需要一个高效的路由协议以对抗复杂的信道环境。无状态几何路由(G-STAR)是一种采用贪婪转发模式的地理路由协议,在大多数3维物联网情景中能够找到合适的数据传输路径,然而水下环境中存在诸多不利因素制约了G-STAR的性能。对此,该文提出一个混合G-STAR(Hybrid G-STAR, H-G-STAR)协议,在保有G-STAR优势的基础上对协议在水下环境中的适应性进行了针对性设计。通过增加基于信道监听的无协作转发策略,在节点数量足够时自发地选择信道状况最佳的路径进行路由,由此避开贪婪转发在水下环境中可能遭遇的极端劣化信道。仿真结果显示H-G-STAR协议相较于基准G-STAR协议有着更好的路由性能,并且在物理层能够取得更低的误比特率(BER),在水下节点的网络拓扑中更为适用。     

移动自组织网路由稳定性分析

针对移动自组织网络中的路由建立和维护问题,研究了衡量路由稳定性的准则,以节点的不确定性特征作为路由选择的标准,提出了基于局部拓扑结构变化熵度量的稳定路由选择策略,并在此基础上设计了一种稳定路由协议。通过NS-2仿真软件对路由选择策略和路由协议进行了验证,仿真结果表明所提出的稳定路由选择策略和路由协议能够有效地提高移动自组织网络的性能。     

基于拓扑感知的水下传感网络路由

由于水下传感网络的高时延、低带宽和高能耗等特性,建立路由协议仍存在挑战。为此,提出基于拓扑感知的水下传感网络路由(TAR)。TAR路由先通过交互Beacon包,使每个节点获取网络拓扑信息,并建立邻居信息表。再依据节点剩余能量和链路的可靠性,择优选择下一跳转发节点,进而提高路由的稳定性,平衡节点间能耗。仿真结果表明,提出的TAR路由增强了路由稳定性,并减少了节点的能耗。     

水下传感器网络路由协议研究

现有水下传感器网络路由协议都属于地理路由协议,需要知道各个节点的水下三维位置信息,从而导致大量水下通信,难以有效延长网络生存时间。本文深入分析了现有研究的不足,提出一种基于深度信息与能量均衡的水下路由协议,只需要节点深度信息,节点间通信量极少;设计了协议的算法,并提出了空洞处理对策。     

ad hoc网络中一种基于信任模型的机会路由算法

由于ad hoc网络具有缺乏足够的物理保护、拓扑结构动态变化、采用分布式协作、节点的带宽和计算能力有限等特点,导致传统的路由安全机制不再适合ad hoc网络路由协议的设计。最近当前研究热点之一的机会路由能够在链路不可靠的情况下充分利用无线广播和空间多样性的特性提高网络的吞吐量。因此,考虑在机会路由中引入信任相似性概念设计信任机会路由,建立了基于节点信任度和最小成本的信任机会转发模型,提出了最小成本的机会路由算法MCOR,并对算法进行了理论上的分析和证明。最后采用仿真实验对该算法进行验证,又与经典机会路由协议ExOR以及其他经典的信任路由协议TAODV和Watchdog-DSR进行性能对比。仿真结果表明,MCOR算法能够防范恶意节点的攻击,在吞吐量、端到端时延、期望转发次数(ETX)和成本开销等方面都比其他3种协议表现出性能上的优势。     

移动Ad Hoc网络路由协议性能仿真对比分析

基于OPNET仿真平台,通过考察节点移动速度、节点移动暂停时间、节点密度和发包间隔对路由协议性能的影响,全面地研究了移动AdHoe网络中典型路由协议的性能。为了公平地对比按需驱动类路由协议和表驱动类路由协议,采用了归一化路由负载作为路由开销的性能指标,最后对3个方面的路由协议性能进行对比和分析。结果表明,仿真结果和理论分析是相符的,因此采用的方法是正确的。     

一种基于AODV的链路质量与能效优先的跨层路由协议

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.     

基于NS-3的声电协同网络实现及路由性能分析

水下无线通信主要依靠水声通信的方式进行信息传输。但水声链路本身具有高时延和高误码率等不足,为水下应用提供低时延的通信服务是一项具有挑战性的工作。声电协同网(CRAN)旨在充分利用水面无线电链路弥补水声网络(UAN)的性能局限,提升网络的整体性能。其中,CRAN中的路由协议需要构建声、电混合路径,是声电协同网络研究中的关键问题。该文首先在网络模拟器3(NS-3)中设计并实现了声电浮标节点与CRAN协议栈,搭建了CRAN的仿真平台。随后探讨了以无线自组网按需平面距离向量路由协议(AODV)为代表的被动式路由在CRAN中的应用。该文发现,AODV协议使用的距离向量准则在CRAN中能够更多地选择高速的无线电链路进行数据转发,有效地降低了网络传输时延。最后,通过仿真对AODV与其他协议的性能进行了对比、分析。结果表明,CRAN在投递率、传输时延、网络吞吐量、能效和路由响应速度方面对比水声通信网有较大提升。同时,以AODV为代表的被动路由协议,相比于以优化链路状态路由协议(OLSR)为代表的主动路由协议更适用于CRAN。     

一种改进的链路容量优化路由策略

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。     

OBS路由协议的FPGA实现方案

研究了光突发交换（OBS）网络路由协议。以FPGA芯片EP2C20Q240C8为基础,通过模拟OBS节点之间的通信,对协议的4类帧的通信流程进行了验证。最后,对该路由协议的时序仿真结果、资源占用情况和时延进行了分析,结果表明,该OBS路由协议实现方案能够满足OBS网络的通信要求。     

Implementation of depth‐based routing and its enhancement in AquaSim–Next Generation for underwater wireless sensor networks

In the last decade, underwater wireless sensor networks have been widely studied because of their peculiar aspects that distinguish them from common terrestrial wireless networks. Their applications range from environmental monitoring to military defense. The definition of efficient routing protocols in underwater sensor networks is a challenging topic of research because of the intrinsic characteristics of these networks, such as the need of handling the node mobility and the difficulty in balancing the energy consumed by the nodes. Depth‐based routing protocol is an opportunistic routing protocol for underwater sensor networks, which provides good performance both under high and low node mobility scenarios. The main contribution of our work is presenting a novel simulator for studying depth‐based routing protocol and its variants as well as novel routing protocols. Our simulator is based on AquaSim–Next Generation, which is a specialized tool for studying underwater networks. With our work, we improve the state of the art of underwater routing protocol simulators by implementing, among other features, a detailed cross‐layer communication and an accurate model of the operational modes of acoustic modem and their energy consumption. The simulator is open source and freely downloadable. Moreover, we propose a novel and completely distributed routing protocol, named residual energy–depth‐based routing. It takes into account the residual energy at the nodes' batteries to select the forwarder nodes and improve the network lifetime by providing a more uniform energy consumption among them. We compare its performance with that of depth‐based routing protocol and a receiver‐based routing protocol implementing a probabilistic opportunistic forwarding scheme.     

A Vector-Based Routing Protocol in Underwater Wireless Sensor Networks

One major concern shared by many researchers about underwater wireless sensor networks (UWSNs), with respect to the limitations and particularities of underwater environment, is the problem of routing. These limitations include three-dimensional topology, limited bandwidth, node movement, long delay, limited energy, and construction costs. The new routing protocols for underwater networks have been developed on the basis of voracious routing systems. The main problem with UWSNs is finding an efficient route between the source and the target to send more packets to the target with lower levels of energy consumption. In this research, by improving VBF algorithm, which is dependent on the radius of the routing pipe, an algorithm is introduced which considers pipe radius as a function of the environment’s dimensions and of the range and the number of nodes. Consequently, by changing one of these parameters, the radius of the routing pipe changes. However, to control the energy consumed by the nodes, there exists a function that, if the recipient node’s energy to receive the packet is much lower than that of the sender node, the proposed method reduces the size of the routing pipe’s radius to lessen its chance of being selected as the guiding node so that other nodes are able to have the chance of getting the packet’s guiding node. The proposed algorithm has been compared with VBVA, HHVBF, and VBF protocols; the simulation results obtained from NS-2 simulator indicate that the proposed protocol could cut back on energy consumption, especially in networks with high number of nodes, by relying on changing the width of the routing pipe in proportion to network density. It was also successful in delivering more packets in non-dense networks.     

A Proposal of B-Tree Based Routing Algorithm for Monitoring Systems with Regular Movements in MANETs

Routing Protocols in MANETs have been researched for peer-to-peer services in general. Furthermore, these protocols have been concerned with the fairness service amongst nodes’ peers. However, most of those protocols aren’t suitable for the data communication especially in hierarchical networks, where the most data flows are vertical like a monitoring system. Furthermore, for the monitoring system, amongst the nodes, one of them (a.k.a. root node) should be employed as a gateway to connect to Internet. Thus, most reporting data from certain nodes are delivered to the root node. Likewise, data should be delivered to the message originator nodes for responsibility. Therefore, a new routing protocol for such networks including the monitoring system is strongly required. This paper proposes a routing protocol based on the binary-tree shaped network, which derives from the general table driven methods’ routing manners with DSDV families of MANETs. In conclusion, we verify whether our protocol would be efficiently used in such networks through its performance evaluations with simulation results.     

A Distributed Energy-Aware Routing Protocol for Underwater Wireless Sensor Networks

The design of routing protocols for Underwater Wireless Sensor Networks (UWSNs) poses many challenges due to the intrinsic properties of underwater environments. In this paper we present DUCS (Distributed Underwater Clustering Scheme), a new GPS-free routing protocol that does not use flooding techniques, minimizes the proactive routing message exchange and uses data aggregation to eliminate redundant information. Besides, DUCS assumes random node mobility and compensates the high propagation delays of the underwater medium using a continually adjusted timing advance combined with guard time values to minimize data loss. The theoretical and simulation studies carried out demonstrate its effectiveness.     

路由信息的攻击对AODV协议性能的影响分析

AODV协议是移动自组网络中一种按需反应的表驱动路由协议。在移动自组网中，每个节点既是计算机又是路由器，容易遭受基于路由信息的网络攻击，而现今的路由协议基本没有考虑到该问题。本文在分析移动自组网中针对路由信息主要攻击方法的基础上，建立了主动性和自私性两个攻击模型，并且在AODV协议中扩充实现了这两类攻击行为。通过对模拟结果的分析和比较，讨论了路由信息的攻击对AODV协议性能的影响，并进一步探讨了针对基于路由信息攻击的防御措施。     

网络编码在无线Mesh网络中的研究与实现

Mesh网络沿用了Ad Hoc网络中的路由协议,但Mesh网络节点移动性高,路径的生存周期短,根据无线Mesh网络自身的动态特点进行路由协议的优化成为了研究的热点。COPE编码方案是针对Mesh网络中的单播特性提出的一种新的机会网络编码机制,能够提高网络的吞吐量。通过NS2仿真平台对AODV路由协议添加COPE网络编码方案,仿真结果表明在不同网络条件下,AODV和COPE的结合增加了无线节点的编码机会,使网络的吞吐量得到了有效的提高。     

End-to-End Delay and Energy Efficient Routing Protocol for Underwater Wireless Sensor Networks

Providing better communication and maximising the communication performance in a Underwater Wireless Sensor Network (UWSN) is always challenging due to the volatile characteristics of the underwater environment. Radio signals cannot properly propagate underwater, so there is a need for acoustic technology that can support better data rates and reliable underwater wireless communications. Node mobility, 3-D spaces and horizontal communication links are some critical challenges to the researcher in designing new routing protocols for UWSNs. In this paper, we have proposed a novel routing protocol called Layer by layer Angle-Based Flooding (L2-ABF) to address the issues of continuous node movements, end-to-end delays and energy consumption. In L2-ABF, every node can calculate its flooding angle to forward data packets toward the sinks without using any explicit configuration or location information. The simulation results show that L2-ABF has some advantages over some existing flooding-based techniques and also can easily manage quick routing changes where node movements are frequent.     

基于移动Agent的LEACH协议的研究与改进

无线传感器网络中路由协议最重要的设计目标是避免节点过早死亡,延长网络生存时间。文中在原有层次式路由协议LEACH的基础上,提出了一种新的MA-LEACH（Mobile Agent LEACH）路由协议,MA—LEACH中引入了移动Agent计算模式,避免了大量的感知数据在网络中传输,由移动Agent移动到感知节点进行本地处理。仿真实验表明,MA-LEACH比原有LEACH协议在降低节点能耗,延长网络寿命等方面上有了显著提高。     

水声网络通信性能分析

该文根据水声信道传播特性及水声网络结构特征,建立了基于水声网络的通信性能分析模型,并仿真分析了对等网络和汇聚网络两种水声网络结构的通信性能与节点间距、网络规模、工作繁忙度以及发射功率等因素的联系,结果表明通过适当的网络设置和协议设计能够优化网络的通信性能,并且存在使通信带宽效率最优的水声网络节点间距。该文的研究成果对水声网络应用具有指导意义。