无线传感器网络LEACH路由算法改进

在分析了无线传感器网络中分层路由LEACH算法的基础上,根据网络中节点初始能量的不同,提出了一种新型簇首节点选择方法,并通过MATLAB对改进后的LEACH算法进行了仿真,仿真结果显示改进后的LEACH算法充分利用了网络的功耗。     

航空电子系统中FC网络的仿真和延迟估计

对采用单交换机光纤通道(FC)网络的航空电子系统进行了描述,建立了网络的排队模型.根据M/G/1模型对FC网络的队列长度、服务时间等参数进行了分析和估计.在OPNET平台下对4种周边节点数不同的FC网络进行了仿真;通过仿真分析了FC网络端到端延迟和网络节点数关系,并对评估的数学模型进行了修正;研究了网络中的延迟"抖动"...     

基于Ad hoc的按需路由协议DSR的优化研究与实现

无线Ad hoc网络是一种不需要基础设施的自组织和自管理网络,网络中所有的节点同时具有终端和路由器的功能。因此网络可以通过节点路由发现机制转发分组,并进行路由维护。文中对DSR(动态源路由协议)的路由发现过程进行了优化,并采用OPNET仿真软件对基于DSR协议的Ad hoc网络的路由开销和时延等关键参数进行了仿真统计,分析了改进后的路由协议对网络质量的影响。     

基于OPNET的3G-ALE多址接入协议仿真分析

由于短波资源有限,研究短波网络多址接入协议尤为重要。介绍了第3代短波自动链路建立协议（3G-ALE）所采用的新技术,然后对3G-ALE协议多址接入算法进行了分析。在OPNET网络仿真平台,独立设计完成了3G-ALE节点模型、相关进程模型及网络模型,对自动链路建立过程进行了仿真,并进行了不同情况下节点建链成功率的仿真分析。结果表明,信道误码率对节点建链成功率影响最明显,信道数量和网络节点数次之,节点业务量对建链影响最小。     

移动Mesh网络定位系统研究

提出了一种基于移动Mesh网络的定位系统,利用Mesh节点作为"锚"节点,建立相对坐标系,移动终端通过测量与"锚"节点之间距离,并通过TDOA定位算法获得自身相对位置信息。对移动Mesh网络定位系统可行性问题进行探讨,主要对移动Mesh网络条件下实现终端定位的性能进行了探讨,并对定位误差进行了必要的仿真验证。仿真结果表明该系统定位精度较高,可实现基于移动Mesh通信网络的终端定位功能。     

基于NS2的OBS网络仿真平台研究与实现

给出了一种基于NS-2的OBS网络仿真平台--OBS-NP(OBS-NS2-platform).该平台通过扩展NS-2中的节点类与链路类,支持对光突发交换(OBS)网络的运行及关键算法的仿真.在详细描述OBS-NP系统构成的基础上,以一个9节点OBS网络为基础,对网络中突发包的时延、吞吐量和资源利用率进行了仿真,并给出了突发包的路由信息.最后,对OBS-NP仿真结果的准确性进行了分析和讨论.     

无线Mesh网络中激励机制研究

为了激励无线Mesh网络中自私节点转发数据,通过分析节点自私行为激励的原因和目标,将适用于无线Mesh网络中对节点自私行为的四类激励机制进行比较.讨论了无线Mesh网络博弈模型,并对无线Mesh网络中重复博弈模型进行理论分析.针对节点的自私行为提出了基于博弈论与信誉相结合的激励方案.仿真实验表明,该方案不仅降低了基于信誉的复杂度又能有效激励更多自私节点转发数据,从而提高了网络的整体性能.     

基于OPNET的地域通信网网络仿真研究

针对无线通信情况下地域通信网中心交换机节点间的通信质量,采用模块化的方法描述节点对象的行为并对节点进行建模,通过OPNET网络仿真工具对地域通信网各网络节点的仿真模型以及组成各节点的进程模块进行设计实现,结合地域通信网的一个实例,得出了节点受不同干扰情况下的全局数据业务丢包率和话音业务呼损率。     

复杂信息系统网络脆弱性分析及仿真验证技术

现今,基于模拟攻击造成的复杂信息系统网络脆弱性问题主要通过节点度数等物理指标降序攻击进行分析,但忽视了数据业务层面造成的影响。本文主要结合电力信息网络的三层物理结构以及星型业务特点,进行节点偏移修正,在此基础上,对复杂信息系统网络脆弱性进行模拟攻击分析,并进行仿真验证。结果表明：基于节点修正偏移量进行复杂信息系统网络脆弱性分析有效。     

紫外光无线传感器网络节能的研究与仿真

为了减少无线传感器网络节点的能量消耗,采用紫外光作为无线传感器网络的信息载体,研究了紫外光传感器节点的能量模型。理论分析了单跳节能和多跳节能,得出了计算最优跳数的数学表达式,并对单跳通信、多跳通信和最优跳通信的平均能量消耗进行了计算机仿真,仿真结果与理论分析一致;对于多跳通信带来的能量消耗不均匀的问题,利用移动sink节点来解决,通过仿真对比了sink节点不同移动速率对网络平均能量消耗、丢包率和端到端时延的影响。结果表明,借助移动sink节点可以降低网络的平均能量消耗,但要根据场景选择合适的移动速率。     

IEEE802.15.4时隙CSMA/CA算法性能研究

对IEEE802.15.4标准和时隙CSMA/CA算法进行了简单介绍,基于OPNET仿真软件,针对节点个数、工作周期(占空比)等参数对时隙CSMA/CA算法性能的影响,进行了不同网络环境的仿真实验。分别在固定节点个数和固定占空比条件下,仿真并分析了介质接入时延与吞吐量及网络能耗之间的关系。仿真结果表明,较多的节点个数和较小的工作周期会增大介质接入时延,降低网络吞吐量。     

The Impact of Deployment Pattern and Routing Scheme on the Lifetime in Multi-Sink Wireless Sensor Network

Extensive use of sensor and actuator networks in many real-life applications introduced several new performance metrics at the node and network level. Since wireless sensor nodes have significant battery constraints, therefore, energy efficiency, as well as network lifetime, are among the most significant performance metrics to measure the effectiveness of given network architecture. This work investigates the performance of an event-based data delivery model using a multipath routing scheme for a wireless sensor network with multiple sink nodes. This routing algorithm follows a sink initiated route discovery process with the location information of the source nodes already known to the sink nodes. It also considers communication link costs before making decisions for packet forwarding. Carried out simulation compares the network performance of a wireless sensor network with a single sink, dual sink, and multi sink networking approaches. Based on a series of simulation experiments, the lifetime aware multipath routing approach is found appropriate for increasing the lifetime of sensor nodes significantly when compared to other similar routing schemes. However, energy-efficient packet forwarding is a major concern of this work; other network performance metrics like delay, average packet latency, and packet delivery ratio are also taken into the account.

     

一种应用于移动P2P网络的资源协作共享策略

移动P2P网络的移动节点设备资源短缺,网络动态多变,移动节点间的协作显得越发重要.本 文提出了一种灵活的移动节点间资源协作共享方案,为资源的请求者设计了基于可靠性理论 的请求资源预测算法.依据排队理论为资源的提供者,构建了层次型资源调度模型.数学分析 和仿真结果表明该预测算法提高了节点请求任务执行成功率,层次型资源调度模型则提高了 节点协作共享资源的服务能力,降低了资源请求丢失率.     

Probabilistic analysis of routes on mobile ad hoc networks

The ad hoc network is comprised of mobile nodes without wires or any infrastructures. All data are transmitted from source node to destination node through wireless channels. The ad hoc network is self-organized by ad hoc network routing protocols. Due to the mobility of nodes, the route which is constructed from many proposed ad hoc network routing protocols and comprised of several direct node-to-node links exists only for a certain period. That also means the route is subject to frequent breakages. In this letter, the probabilistic behavior of a constructed route is investigated through simulation and curve fitting. The simulation results show that the probability density function of a route is exponential distribution. The simulation also shows how the time proportion is distributed among different route lengths under a certain scenario. The route is a basic factor in the ad hoc network which operates without any central controller. The characteristics of the route have much influence on the performance of the ad hoc network. Thus the probabilistic analysis provides important implications when we are designing ad hoc network routing protocols and deploying ad hoc networks.     

BS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。     

移动混合传感网中节点自主部署算法

针对节点感知半径不均衡的移动传感网络节点的部署问题,论文提出一种基于VL(Voronoi Laguerre)图分割的节点自主部署算法(Autonomous Deployment Algorithm, ADA)。ADA先对目标区域做VL图划分,将目标区域的覆盖任务在各个传感器节点之间进行分配。分配到覆盖子区间任务的节点通过构造VL受控多边形来确定下一轮候选目标位置。未分配到覆盖子区间的节点则根据自身与邻居节点感知圆及目标区域边界的几何位置关系计算所受虚拟力,最终确定下一轮目标点坐标。网络各个节点通过逐轮更新自身位置,从而提高网络覆盖。仿真结果表明,ADA算法在网络覆盖率、节点部署速度和节点分布均匀性等方面具有明显的优势。     

EEAODR: An energy‐efficient ad hoc on‐demand routing protocol for mobile ad hoc networks

Mobile ad hoc networks (MANETs) are characterized by random, multi‐hop topologies that do not have a centralized coordinating entity or a fixed infrastructure that may change rapidly over time. In addition, mobile nodes operate with portable and finite power sources. In this work, we propose an energy‐efficient routing protocol for MANETs to minimize energy consumption and increase the network's consistency. Traditional works mainly focused on the shortest path‐based schemes to minimize energy, which might result into network failure because some nodes might exhaust fast as they are used repetitively, while some other nodes might not be used at all. This can lead to energy imbalance and to network life reduction. We propose an energy‐efficient ad hoc on‐demand routing protocol that balances energy load among nodes so that a minimum energy level is maintained among nodes and the network life increases. We focused on increasing the network longevity by distributing energy consumption in the network. We also compared the simulation results with a popular existing on‐demand routing protocol in this area, AODV, to establish the superiority of our approach. Copyright © 2009 John Wiley & Sons, Ltd.     

Double Cluster Based Energy Efficient Routing Protocol for Wireless Sensor Network

Reducing the energy consumption of sensor nodes and prolonging the life of the network is the central topic in the research of wireless sensor network (WSN) protocol. The low-energy adaptive clustering hierarchy (LEACH) is one of the hierarchical routing protocols designed for communication in WSNs. LEACH is clustering based protocol that utilizes randomized rotation of local cluster-heads to evenly distribute the energy load among the sensors in the network. But LEACH is based on the assumption that each sensor nodes contain equal amount of energy which is not valid in real scenarios. A developed routing protocol named as DL-LEACH is proposed. The DL-LEACH protocol cluster head election considers residual energy of nodes, distance from node to the base station and neighbor nodes, which makes cluster head election reasonable and node energy consumption balance. The simulation results of proposed protocols are compared for its network life time in MATLAB with LEACH protocol. The DL-LEACH is prolong the network life cycle by 75 % than LEACH.     

A local synchronization-based wireless system for power efficient ad-hoc networks

In a scalable ad-hoc network, which is deployed in a large area with many nodes, it is difficult to maintain global time synchronization among all nodes in a whole network. Considering this problem, a local synchronization-based system is presented to discover neighboring nodes in a scalable wireless network. With the proposed system, a whole ad-hoc network is composed of several subgroups and local time synchronization is maintained within each subgroup. For the proposed system, the transmitter and receiver operations of a node are presented to discover neighboring nodes. The most important parameter for power consumption is the duty cycle of a node, defined as the ratio between the receiver turn-on time and total considered time. The duty cycles of the proposed system and cyclic quorum-based power management (CQPM) are compared by analysis. In addition, the power consumptions of the proposed system and CQPM are compared by simulation. The results show that the proposed system can reduce the power consumption of a node significantly in a scalable ad-hoc network.     

WSNs中基于数据匹配的分布式故障节点检测算法

针对无线传感网络的节点故障问题,提出一种新的分布式故障节点检测算法(DFDA)。DFDA算法利用节点度信息估计节点对网络的重要性,并尽可能将节点度高的节点保存到网络中。通过比较节点间感测的数据,检测故障节点。为了增强检测的准确性,采用双重测定策略。仿真结果表明,相比于同类算法,DFDA算法提高了检测故障节点的精确度,并降低了虚警率。