220D无线自组网路由拓扑更新分析与优化

拓扑更新是无线自组网路由协议的重要组成部分,是影响网络性能的关键因素。220D无线自组网路由协议规定其节点在每个最小时间间隔内最多发送一次拓扑更新消息。针对最小时间间隔值设置不合理时,会影响网络性能的问题,提出一种自适应改变最小时间间隔值的路由拓扑更新优化方法,仿真结果显示该方法可以改善网络性能。     

一种基于信噪比的自组网功率控制算法

能量是影响无线自组网性能的一个很大的瓶颈,作为事实上的无线自组网媒体接入协议,802.11并没有动态调整传输功率的能力,网络在实际应用中的节能效果不好.为了降低网络节点的能量消耗,在媒体接入层802.11协议基础上,,提出一种功率控制算法,以物理层信噪比为基础估计控制帧和数据帧的发送功率.通过OPNET网络仿真软件对算法进行了计算机仿真,仿真结果表明.相比802.11协议,算法有效降低了节点能量消耗,提高了能量利用率,延长了网络的生存时间,同时保持了网络的吞吐量性能,对自组网的理论研究和实际应用提供了一定的参考价值.     

移动Ad Hoc网络DSR路由协议性能分析

无线移动Ad Hoc自组网是由不依赖任何已有的网络设施的移动节点组成,该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.Ad Hoc网络路由协议中DSR路由协议在不同发包率和节点移动速率的情况下各项网络性能都优于其他路由协议,尤其当网络业务量不大时性能更优.基于路由缓存大小和路由更新时间对协议性能的影响,利用OPNET建立DSR路由协议的Ad Hoc网络,并对路由出错、路由开销和时延等关键参数的仿真统计.仿真结果与理论分析一致,一般地,随着路由缓存变大和路由更新时间变短,网络中路由出错、路由开销和时延性能都有所提高.     

一种能量感知的无线移动自组网路由协议

无线移动自组网中的大多数节点都是由有限寿命的电池来提供的,能量保护策略就成为设计网络协议的一个重要条件。提出一种能量感知的无线移动自组网路由协议,综合考虑了节点的剩余能量和路由跳数,有效保护网络中能量低的节点,减少了节点能量损耗,延长了网络的使用时间。该路由协议中采用了局部路由修复机制,减少了数据包丢失,提高了数据传输率。最后,仿真结果证明了协议的有效性。     

一种新的基于DSR的移动自组网节能路由策略

移动自组网是由一组带有无线收发装置的移动节点组成的一个支持多跳的临时性的网络自治系统。由于移动自组网的大多数节点是由有限寿命的电池来提供的，因此能量保护策略成为制定路由协议的一个重要依据。该文提出了一种新的基于动态源路由协议的节能路由策略。仿真表明该策略有效地延长了网络的生存时间。并很好地均衡了节约能耗和保护网络传统性能的需求。     

基于能量消耗的Ad Hoc网络路由协议的研究

在移动自组网Ad Hoc网络中,链路中的节点一般都是采用电池供电,一旦电池电量耗尽,节点就会离开链路,造成网络中断,因此降低节点的能量消耗对保持链路的稳定至关重要,本文给出了基于最大能量邻居节点的路由发现算法,提出了基于AODV协议改进的Ad Hoc网络路由协议PER-AODV,该协议能够确保延长网络的生存时间和对低能量节点的保护以及重构次数的减少。     

基于改进萤火虫群优化的无线自组网路由算法

针对无线自组网络拓扑结构多变、网络生存时间受限及数据包分组传输效率低下等问题,借鉴萤火虫群优化算法,提出了一种改进萤火虫群优化的无线自组网络路由算法.路由算法将萤火虫优化算法中的荧光素强度更新与无线自组网络中的节点移动速度、拥塞程度、节点剩余能量、节点间距离等因素进行相互映射,同时改进萤火虫群优化算法中的搜索萤火虫、驻留萤火虫及回溯萤火虫用于完成无线自组网络中路由协议的路由发现、路由选择及路由维护等过程,整个协议无须传送大量的控制分组,即可实现无线自组网络的稳定传输.仿真实验结果表明,与AODV及基于蚁群优化的路由算法AntRouting协议相比,本文所提出的路由算法在端到端延时、分组数据传输率及网络生存时间上均有良好的性能.     

一种基于剩余能量和负载的AODV路由协议

移动自组网中的按需距离矢量路由协议(AODV)是基于最小跳数的,没有考虑能量消耗均衡及网络生命周期的问题,造成某些节点过早死亡。针对这一问题,提出了一种基于剩余能量和节点缓存队列负载的路由协议,有效地避免了能量较低和负载较重的节点参与路由。仿真实验结果表明,所提出的新协议有效地减少了端对端平均延时,延长了网络生命周期。     

基于稳定链路MANETs路由协议的研究现状

移动自组网(MANETs,mobile Ad Hoc networks)中节点随机移动,且无固定基础设施、节点能量受限等诸多的因素影响了链路的稳定性,给路由协议提出了挑战.目前,研究人员对基于稳定链路的路由协议进行了深入的研究,并提出不同的基于稳定链路的路由协议.为此,首先对现有的基于稳定链路的路由协议进行分类,然后,分析了每类的经典协议的性能,最后,讨论基于稳定链路的路由协议的未来发展方向.     

自组网环境下具有能量和移动感知的自适应路由协议

自组网是由一组带有无线收发装置的移动节点组成的一个能够支持多跳的临时性的通信网络，动态拓扑变化是它的最大特征之一；此外，由于自组网的大多数节点是由有限寿命的电池来提供的，能量保护策略成为设计该类网络协议的一个重要依据。文章提出了一种基于动态源路由的具有能量和移动感知的自适应路由协议，仿真表明该协议有效地延长了网络的生存时间，并提高了网络吞吐量。     

An efficient hop count routing protocol for wireless ad hoc networks

An efcient hop count route fnding approach for mobile ad hoc network is presented in this paper.It is an adaptive routing protocol that has a tradeof between transmission power and hop count for wireless ad hoc networks.During the route fnding process,the node can dynamically assign transmission power to nodes along the route.The node who has received route request message compares its power with the threshold power value,and then selects a reasonable route according to discriminating algorithms.This algorithm is an efective solution scheme to wireless ad hoc networks through reasonably selected path to reduce network consumption.Simulation results indicate that the proposed protocol can deliver better performances with respect to energy consumption and end-to-end delay.     

An Efcient Hop Count Routing Protocol for Wireless Ad Hoc Networks

An efcient hop count route fnding approach for mobile ad hoc network is presented in this paper.It is an adaptive routing protocol that has a tradeof between transmission power and hop count for wireless ad hoc networks.During the route fnding process,the node can dynamically assign transmission power to nodes along the route.The node who has received route request message compares its power with the threshold power value,and then selects a reasonable route according to discriminating algorithms.This algorithm is an efective solution scheme to wireless ad hoc networks through reasonably selected path to reduce network consumption.Simulation results indicate that the proposed protocol can deliver better performances with respect to energy consumption and end-to-end delay.     

基于加权路由思想的无线自组织网络生存时间优化算法研究

在无线自组织网络中,网络生存时间是衡量网络性能的重要指标之一.分析影响网络生存时间的众多因素后,提出了一种工作量加权路由模型以提高无线自组织网络的生存时间.在网络信息传输的过程中,综合每条链路的业务工作量对网络链路进行加权,建立距离加权传输数学模型.该模型通过降低工作较为繁忙节点的信息转发概率,从而到达均衡节点能耗的目的.最后,采用MATLAB进行数值仿真,结果显示本文提出的路由算法可以有效延迟网络生存时间,均衡网络节点的能耗.     

一种快速而高效的MANET路由协议

MANET是一种由一系列可以自由移动的节点主机聚集而成的一个临时性动态网络。由于其拓扑的动态性,其路由协议与其它传统网络有着很大的区别。传统的MANET路由协议都在路由破裂后由源节点重新建路,存在较大建路延时,极大阻碍了信息的实时传送。为此,该文提出了一种支持实时传送的路由协议,该协议通过在路由破裂处用最快方法重新建路来实现数据的实时传输。模拟结果表明这种协议具有较好的网络性能。     

Energy saving and capacity improvement potential of power control in multi-hop wireless networks

This study investigates the potential of using transmission power control in wireless packet networks with differing number of hops between source and destination nodes. Here we exploit the benefits of power control in the context of multi-hop wireless ad hoc type networks with a distributed media access control. For our investigations we choose several general ad hoc network topologies and study the effects of power control with respect to energy consumption and network capacity. We show that power control largely improves the network capacity and energy savings in all investigated scenarios, and that utilizing a greater number of intermediate hops between source and destination nodes improves the energy savings though may cause a tradeoff in capacity, depending on the network topology considered.     

Analysis of a Randomized Congestion Control Scheme with DSDV Routing in ad Hoc Wireless Networks

Ad hoc wireless networks are expected to play an increasingly important role in future civilian and military settings where wireless access to a wired backbone is either ineffective or impossible. However, frequent topology changes caused by node mobility make routing in ad hoc wireless networks a challenging problem. In addition, limited capabilities of mobiles require a control on node congestion due to message forwarding.  In this paper, we present a randomized version, called R-DSDV, of the known destination-sequenced distance vector (DSDV) routing protocol for ad hoc networks and analyze its capabilities for distributed congestion control. The analysis is based on a novel approach that uses Markov chains for representing the distribution of routing information over the network. Our results indicate that a probabilistic congestion control scheme based on local tuning of protocol parameters is feasible and that such a mechanism can be effective in reducing the amount of traffic routed through a node which is temporarily congested. The traffic reduction is almost linear with respect to the decrease in the R-DSDV routing table advertisement rate of the congested node. On an average, the convergence time is relatively small as compared to the transmission rates of protocol messages.     

移动自组织网络基于极端预测的节能路由算法

在移动自组织网络中,减少移动节点电池能量消耗,延长网络生存时间,是路由协议性能优劣的一个重要指标.针对这一问题,提出了一种基于极端预测的路由算法,根据门限值划分节点稳定域,计算链路有效性,以最大最小路径有效性原则选路.同时,节点根据下一跳节点的位置自动调整发射功率,以达到节能的目的.仿真结果表明该算法与DSR相比能有效...     

高能量节点驱动的按需距离矢量路由协议

无线自组织网络中的按需距离矢量路由协议(AODV)没有考虑到能量消耗的均衡性和网络生命期的问题。针对AODV的这一缺点,提出了一种高能量节点驱动的AODV协议(HN-AODV)。此协议将高能量节点驱动的策略应用于按需路由发现过程,尽量选择能量较高的节点来承担转发任务,以此来平衡网络能耗。仿真结果显示,HN-AODV在基本不降低数据传输性能的前提下,显著提高了网络生命周期。这种高能量节点驱动的方案同样可以运用在其它类似的反应式路由协议中。     

Towards estimating lifetime of ad hoc wireless networks

Ad hoc wireless networks possess highly constrained energy resources. The available energy resources should thus be used efficiently, in order to satisfy the requirements. Hence, the protocols at all the layers of the protocol stack should be energy aware and energy efficient. However, all the existing protocols are not energy aware and perform poorly in the presence of a limited power source. Even the energy aware protocols proposed for ad hoc networks do not consider all the characteristics of the underlying batteries. Hence, they fail to efficiently utilize the available energy. There also exist a few protocols, which, though battery unaware, unknowingly prove to be energy efficient. Thus, a mechanism is required to measure the efficiency of the protocols of ad hoc networks, in terms of the network lifetime. To the best of our knowledge, there has been no reported work till date for analyzing the lifetime of the ad hoc networks for various protocols.The protocols at all the layers of the protocol stack together decide the discharge of the battery source of a node. However, assuming that only the MAC protocols decide the battery performance, we focus on measuring the energy efficiency of MAC protocols. This paper primarily provides a novel generalized analytical model for estimating lifetime of ad hoc networks, in the presence of the following two kinds of MAC protocols: (i) reservation-based TDMA protocols and (ii) a specific class of CSMA protocols that try to follow a pattern, such as a round-robin scheduling, for packet transmission. Our model uses discrete-time Markov chain with probabilistic recovery to model the batteries of the ad hoc nodes. We found that our analytical model accurately estimates the lifetime of the network for various MAC protocols. We prove through analytical and simulation studies that energy awareness is crucial in deciding the performance of the MAC protocols for both homogeneous and heterogeneous ad hoc wireless networks.