Route maintenance of on-demand routing protocol in mobile ad hoc networks

In mobile ad hoc networks （MANETs）, if a mnltihop route breaks, route maintenance is typically performed to establish a new route which causes high control overhead and long packet delay. To decrease the time of recovery and the overhead of maintenance, a new route maintenance mechanism in which the maintenance is confined to the vicinity of the broken link is proposed. This mechanism patches broken route through some other nodes in which only nodes near the broken link（s） may need to be substituted and the rest of nodes can be retained on the route. The broken link can be repaired without considering its relative position in the whole path, so the abihty of dealing with hnk failure is improved obviously. Simulation results show that the proposed strategy improves network performance significantly, such as in merits of control overhead and packet delay.

移动Ad Hoc网快速自适应后备路由协议

移动Ad Hoc网拓扑结构经常变化。自适应后备路由局部修复AODV协议AODV-ABL通过监听RREP包和数据包来产生后备路由,并存于后备路由表中。仅当链路错误时,AODV-ABL才试图利用后备路由表进行局部修复。为提高对网络拓扑变化的自适应性,在AODV-ABL基础上,提出了一种快速自适应后备AODV路由协议AODV-FABL。AODV-FABL合并主路由表和后备路由表,在监听包时同步更新路由,路由能尽快地得到优化。实验结果表明,AODV-FABL取得了比AODV-LR、AODV-ABL更好的包投递率、端对端时延、控制开销和对流量负载变化的适应性。

Adaptive load balancing scheme in ad hoc networks

An adaptive load balancing scheme is proposed to balance the load in ad hoc networks. The new scheme can be applied in most on-demand routing protocols resulting in significant performance improvement. The proposed scheme is applied to the ad hoc on-demand distance vector （AODV） routing protocol. Simulation results show that the network load is balanced on the whole, and performance in packet loss rate, routing overhead and average end-to-end delay is also improved.

Trust-based Intelligent Scheme for Mitigating Black Hole Attacks in IoT

Internet of Things(IoT)networks are characterized by a multitude of wireless,interconnected devices that can dynamically join or exit the network without centralized administration or fixed infrastructure for routing.While multipath routing in IoT networks can improve data transmission reliability and load balancing by establishing multiple paths between source and destination nodes,these networks are susceptible to security threats due to their wireless nature.Traditional security solutions developed for conventional networks are often ill-suited to the unique challenges posed by IoT environments.In response to these challenges,this paper proposes the integration of the Ad hoc On-demand Multipath Distance Vector(AOMDV)routing protocol with a trust model to enhance network performance.Key findings from this research demonstrate the successful fusion of AOMDV with a trust model,resulting in tangible improvements in network performance.The assessment of trustworthiness bolsters both security and routing capabilities in IoT networks.The trust model plays a crucial role in mitigating black hole attacks in IoT networks by evaluating the trustworthiness of nodes and helping in the identification and avoidance of malicious nodes that may act as black holes.Simulation results validate the efficacy of the proposed trust-based routing mechanism in achieving its objectives.Trust plays a pivotal role in decision-making and in the creation of secure distribution systems.By assessing the trustworthiness of nodes,both network security and routing efficiency can be enhanced.The effectiveness of the proposed trust-based routing mechanism is scrutinized through simulations,offering insights into its potential advantages in terms of improved network security and routing performance in the context of the IoT.

Dynamic Cluster Head for Lifetime Efficiency in WSN

Saving energy and increasing network lifetime are significant challenges in wireless sensor networks （WSNs）. In this paper, we propose a mechanism to distribute the responsibility of cluster-heads among the wireless sensor nodes in the same cluster based on the ZigBee standard, which is the latest WSN standard. ZigBee supports ad hoc on-demand vector （AODV） and cluster-tree routing protocols in its routing layer. However, none of these protocols considers the energy level of the nodes in the network establishing process or in the data routing process. The cluster-tree routing protocol supports single or multi-cluster networks. However, each single cluster in the multi-cluster network has only one node acting as a cluster head. These cluster-heads are fixed in each cluster during the network lifetime. Consequently, using these cluster-heads will cause them to die quickly, and the entire linked nodes to these cluster-heads will be disconnected from the main network. Therefore, the proposed technique to distribute the role of the cluster head among the wireless sensor nodes in the same cluster is vital to increase the lifetime of the network. Our proposed technique is better in terms of performance than the original structure of these protocols. It has increased the lifetime of the wireless sensor nodes, and increased the lifetime of the WSN by around 50% of the original network lifetime.

混合无线Mesh网络中改进的分层AODV路由协议

路由是无线Mesh网络发展中的一个研究热点。无线Mesh网络从移动Adhoc网络中借鉴了许多路由选择算法作为路由的解决方案,但是这些方法都不太理想或者没有达到性能的最优化,且没有利用到无线Mesh网络自身的特点。提出了一个改进的分层AODV路由协议(IH-ADOV),它表现出了更好的可扩展性和网络性能,当一条路由丢失时,它使寻找替代路由的路由开销得到降低。在IH-AODV中,还提出了一种新技术,即最新链路发现机制。利用NS-2软件对AODV和IH-AODV进行了仿真比较。基于混合无线Mesh网络的仿真结果表明,IH-AODV在大的网络中也表现出了很好的扩展性,相对于AODV,在其他性能方面也表现良好甚至更优。

High efficiency AODV routing protocol based on link availability prediction in MANETs

To cope with the problem of low protocol efficiency of the standard ad hoc on-demand distance vector （AODV） routing protocol with the periodic Hello message broadcast mechanism, a new link availability prediction based strategy is introduced to reduce the amount of Hello messages. In this strategy, a novel wireless link availability prediction model under line-of-sight （LOS） propagation environments is proposed based on which the parameter of Hello Interval in AODV can be dynamically adjusted to achieve the goal of changing the frequency of Hello message broadcasts under different link stability degrees. Simulation results demonstrate that, compared with the standard AODV with the periodic Hello message broadcast mechanism, the proposed protocol effectively reduces unnecessary control message overhead and greatly improves the performance in terms of end-to-end delay and efficiency.

MANET中一种基于信任模型的安全路由协议

节点间的信任关系对MANET网络路由协议的可靠性和安全性有重要意义,由于MANET网络的特性,难以通过传统的方式建立节点间信任关系。提出一个适用于MANET的信任评估模型CETM(Contribution and Evaluation Trust Model),用来度量MANET节点间信任关系,并将此模型应用于AODV协议中,提出了一种新的安全路由协议TAODV。仿真结果表明当网络中存在少于一半的恶意节点时,CETM能有效抵御如诋毁等恶意行为,从而显著地提高了交易的成功率。基于CETM的TAODV建立在可靠的节点信任关系之上,具有较好的安全性。

802.11s中RM-AODV路径选择协议的研究

RM-AODV路径选择协议是IEEE802.11s标准中HWMP路由选择协议的基础。不同于传统AODV协议在第3层使用IP地址路由和跳数作为路由metric,RM-AODV工作在第2层使用MAC地址和空时metric进行路径选择。为了适应无线mesh网络流量呈树状汇聚的特点,IEEE802.11s标准还对RM-AODV进行树状先验式扩展。在典型无线mesh网络拓扑中通过仿真对RM-AODV的路径发现时间进行研究,进一步分析相对根节点的不同位置对路径发现时间的影响。

高能量高信号强度节点优先的AODV路由协议

针对AODV协议只选择具有最少跳数路由,而不考虑节点能量即将耗尽或节点即将离开邻节点传送范围,造成路由频繁中断的问题,提出新的改进方案,在路由发现阶段,选择能量较高和信号强度较强的节点作为路由节点,在路由维护阶段,对能量即将耗尽或即将离开邻节点有效传送范围的节点进行路由备份。仿真实验结果表明改进后的协议能够有效增加数据包投递率和减少平均端到端延时,并能有效减缓能耗速度,提高整个网络的生存期。

危险区域无线侦测指挥系统

基于无线技术,提出一种在危险区域进行侦测及指挥的解决方案。系统采用分层结构,分为探测球层、终端层与指挥中心层。探测球层包含了音视频、空气质量等检测模块。终端层基于Liod开发板和Linux系统,配合无线模块实现音频视频采集、空气质量检测、区域报警等功能,通过Ad Hoc无线自组网络与其他终端以及指挥中心进行通信。指挥中心担负着整体调度的职责。利用该系统,可以实现现场指挥、图片传输、实时音频传输、人员定位、现场地图绘制及远程传输等操作,为危险区域的信息收集以及指挥人员的决策提供有力支持。

Packet Drop Battling Mechanism for Energy Aware Detection in Wireless Networks

Network security and energy consumption are deemed to be two important components of wireless and mobile ad hoc networks(WMANets).There are various routing attacks which harm Ad Hoc networks.This is because of the unsecure wireless communication,resource constrained capabilities and dynamic topology.In order to cope with these issues,Ad Hoc On-Demand Distance Vector(AODV)routing protocol can be used to remain the normal networks functionality and to adjust data transmission by defending the networks against black hole attacks.The proposed system,in this work,identifies the optimal route from sender to collector,prioritizing the number of jumps,the battery life,and security,which are fundamental prerequisites.Researches have proposed various plans for detecting the shortest route,as well as ensuring energy conversions and defense against threats and attacks.In this regard,the packet drop attack is one of the most destructive attack against WMANet communication and hence merits special attention.This type of attack may allow the attacker to take control of the attacked hubs,which may lost packets or transmitted information via a wrong route during the packets journey from a source hub to a target one.Hence,a new routing protocol method has been proposed in this study.It applies the concept of energy saving systems to conserve energy that is not required by the system.The proposed method for energy aware detection and prevention of packet drop attacks in mobile ad hoc networks is termed the Ad Hoc On-Demand and Distance Vector–Packet Drop Battling Mechanism(AODV–PDBM).

Balancing the Power Consumption Speed in Flat and Hierarchical WSN

A combination of a cluster tree routing protocol and an Ad hoc on demand vector (AODV) routing protocol is used in the latest ZigBee standard wireless sensor networks (WSNs) technology.However,the AODV routing protocol has no means by which to take into consideration the power consumption of the nodes during the routing process.Therefore,a new approach is proposed in this paper to balance the power consumption speed and to distribute the responsibilities of routing among flat wireless sensor nodes and the three levels of hierarchical wireless sensor nodes.These three levels are based on the three types of devices,which are used in the ZigBee standard:the coordinator,the routers,and the end devices.In this paper,we have compared the original AODV routing protocol with our extension approach for the distribution of power consumption.Based on the simulation results,our new approach has achieved better performance in terms of increasing the lifetime of the flat wireless sensor network,the personal area network (PAN) coordinator,the routers,and the whole network of the hierarchical wireless sensor network.Additionally,it has better performance in terms of distributing the power consumption among the key nodes of the wireless sensor network.