海上多跳无线自组网路由协议仿真研究

海事卫星通信由于其高昂的价格,难以得到广泛应用。为提高海上船舶通信的效率和经济性,有学者和企业提出了海上多跳无线自组网。然而,由于海面特殊的地理条件,波闭塞效应往往会干扰无线通信所需要的稳定链路,造成连接中断和通信质量下降。为解决以上问题,本文提出一种集合路径路由方法,通过对海上通信链路建模和特征分析,将多个海上节点组织为虚节点,使用虚节点之间的路由方法来增强通信链路的可靠性和稳定性,并利用仿真证明本文提出方案的可行性和高效性。     

IP ADDRESS AUTOCONFIGURATION FOR WIRELESS AD HOC NETWORKS

IntroductionWireless ad hoc networks are gaining increas-ing popularity in recent years because of their easeof deployment. No wired base station or infras-tructure is supported,and each hostcommunicatesone anothervia packetradios. In ad hoc networks,routing protocols are challenged with establishingand maintaining multihop routes in the face of mo-bility,bandwidth limitation and power con-straints. In ad hoc networks,each node( host)acts as a router since routes are mostly multihop.Nodes in …     

Reliable routing algorithm in marine ad hoc networks

A routing algorithm called DNH for increasing efficiency of mobile ad hoe network is presented, which is based on a new cflteflon called TSS (Temporarily Steady State), combining with wireless transmission theory that makes networks topology correspondingly stabilization. Also the DNH algorithm has the characteristics of giving up queuing in a node, but selecting another idle node instead of the node for forwarding data packets if the node has a full throughput. Simulation evaluation shows that selecting another node is better than queuing in a full throughout node if some conditions are satisfied, especially during a sea battle, every warship in ad hoe network wants to contest time and increase propagation reliability. The DNH algorithm can help decrease routing time, and raise efficiency of marine ad hoe networks.     

移动自组网跨层设计：方法与难点

首先分析了跨层设计提出的背景,然后对文献中的跨层设计建议进行了分类,分为无线TCP的跨层设计、基于网络层的跨层设计和以链路层为核心的跨层设计三类,并综述了每一类的典型协议和算法。接着介绍了一个跨层设计框架,分析了其设计思路和实现方式。进而总结了跨层设计面临的难点,包括跨层设计理论研究、性能和代价的权衡、跨层设计建议的共存问题和三层以上跨层设计四个方面。     

自组网无线动态应变检测节点设计

本文设计了高精度自组网无线动态应变采集电路。设计采用TI公司的ZIGBEE解决方案进行无线自组网网络建立,采用恒流式电桥提高传感器的抗干扰能力和精度,并进行ADC驱动电路的分析设计,并进行现场实验。实验表明该方案具有较好的环境适应性、可维护性并具有优异的采集精度,可以满足大型复杂结构的分布式疲劳测试。     

Effects of denial of service attack in mobile ad hoc networks

Mobile ad hoc networks are often deployed in environments where the nodes of the networks are unattended and have little or no physical protection against tampering. The nodes of mobile ad hoc networks are thus susceptible to compromise. The networks are particularly vulnerable to denial of service (DoS) attacks launched through compromised nodes or intruders. In this paper, we investigated the effects of flooding attacks in network simulation 2 (NS-2) and measured the packet delivery ratio and packet delay under different flooding frequencies and different numbers of attack nodes. Simulation results show that with the increase the flooding frequencies and the numbers of attack nodes, network performance drops. But when the frequency of flooding attacks is greater than a value, the performance decrease gets smooth. Meanwhile the packet delay firstly increases and then declines to a value of stability at the end.     

On the network connectivity of platoon-based vehicular cyber-physical systems

In the past few years, vehicular ad hoc networking (VANET) has attracted significant attention and many fundamental issues have been investigated, such as network connectivity, medium access control (MAC) mechanism, routing protocol, and quality of service (QoS). Nevertheless, most related work has been based on simplified assumptions on the underlying vehicle traffic dynamics, which has a tight interaction with VANET in practice. In this paper, we try to investigate VANET performance from the vehicular cyber-physical system (VCPS) perspective. Specifically, we consider VANET connectivity of platoon-based VCPSs where all vehicles drive in platoon-based patterns, which facilitate better traffic performance as well as information services. We first propose a novel architecture for platoon-based VCPSs, then we derive the vehicle distribution under platoon-based driving patterns on a highway. Based on the results, we further investigate inter-platoon connectivity in a bi-directional highway scenario and evaluate the expected time of safety message delivery among platoons, taking into account the effects of system parameters, such as traffic flow, velocity, platoon size and transmission range. Extensive simulations are conducted which validate the accuracy of our analysis. This study will be helpful to understand the behavior of VCPSs, and will be helpful to improve vehicle platoon design and deployment.     

面向铁路应急的MANET安全节点发现协议建模

针对铁路应急通信网络安全问题,通过对其特征的详细分析,提出了面向铁路应急的移动自组网络安全节点发现协议建模,以达到解决铁路应急通信网络安全节点发现问题的目的.在对铁路应急的移动自组网络规则描述的基础上,给出具体的安全节点建模过程,并对其正确性、安全性、执行效率进行了详细的分析.最后以两类具体的安全节点发现过程为实例进行探讨,表明其与传统加密方式结合后,仍保持其有效性.     

一种改进的自组网动态信道分配协议

文章针对节点具有双收发器多信道的自组网,对动态分配协议进行了改进,使得一些短报文可以在没有可用数据信道时直接在控制信道上传输,从而解决信道利用率不高的问题。研究表明,改进后协议的网络吞吐量有了显著的提高。     

An Adaptive Scheme for Neighbor Discovery in Mobile Ad Hoc Networks

The neighbor knowledge in mobile ad hoc networks is important information. However, the accuracy of neighbor knowledge is paid in terms of energy consumption. In traditional schemes for neighbor discovery, a mobile node uses fixed period to send HELLO messages to notify its existence. An adaptive scheme was proposed. The objective is that when mobile nodes are distributed sparsely or move slowly, fewer HELLO messages are needed to achieve reasonable accuracy, while in a mutable network where nodes are dense or move quickly, they can adaptively send more HELLO messages to ensure the accuracy. Simulation results show that the adaptive scheme achieves the objective and performs effectively.