共查询到19条相似文献,搜索用时 93 毫秒
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研究并提出了一种基于位置信息的AODV路由协议的优化方案。它通过动态调整传输功率,使用区域概率广播的两种方法进行优化。经NS仿真后的性能分析比较,在保证不降低其他网络性能的前提下,改进的AODV协议可以有效地提高传输成功率并缩短端到端的网络延时。 相似文献
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提出了一种适用于Adhoc网络中的多媒体会议系统模型,该模型结合了移动IPv6技术和SIP(session initiation protocol)技术,并对传统的AODV(Ad hoc on-demand distance vector)路由算法路由进行了修改,使其可以很好地匹配系统模型.将传统的AODV算法和修改后的算法应用到系统模型中,对会话中移动节点在不同Ad hoc网络间的切换进行了研究.仿真结果显示,修改后的AODV路由算法性能可以将切换时的时延抖动和分组丢失率改善50%左右. 相似文献
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AODV路由协议的改进 总被引:1,自引:0,他引:1
在新建路由时,AODV选择具有最短跳数的路由,未考虑节点的负载,所选的路径可能造成网络拥塞,且在节点移动较快时,性能下降非常厉害。针对这种情况,对其路由发现和维护阶段进行改进,在路由发现时根据节点负载选择节点并且在拓扑改变时动态对路由进行优化,减少网络拓扑变化对路由的影响。仿真结果证明,改进后的协议在减少网络拥塞、降低丢包率等方面较AODV协议均有了改进。 相似文献
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无线Ad Hoc网络是一个临时多跳的自治系统。网络中各节点地位平等,既可以做主机也可以做路由器。Ad Hoc网络有着广泛的应用,已成为当前研究的热点之一。由于Ad Hoc网络拓扑结构频繁变化,本文提出了一种改进的AODV路由协议——R_EAODV。R_EAODV路由协议通过查看每个节点的剩余能量进行链路修复。通过仿真我们发现R_EAOD在分组传送成功率、平均端到端时延、路由开销等性能方面都得到有效的改善,特别是当节点能量不足时进行链路修复以发现新的路由,更适用于拓扑结构变化快的网络环境。 相似文献
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为更好地将移动自组网络用于网络控制系统(NCS),结合NCS的网络特性,提出了一种基于链路信号质量的QoS路由算法。主要QoS机制包括根据接收信号强度选择较稳定的路由;用Hello报文广播节点的预留带宽;中间节点为所有受影响的数据流修复路由、目的节点向源节点广播路由修复报文进行路由修复。NS2仿真表明当节点移动性强时,该QoS路由算法可有效减少网络的平均端到端时延和丢包率,提高控制系统稳定性。 相似文献
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无线Ad Hoc网络中AODV路由算法的研究与改进 总被引:1,自引:0,他引:1
无线Ad Hoc网络是一个多跳的、临时的、对等的自治系统,它由一组带有无线收发信装置的移动节点组成.由于在军事通信、紧急救援、传感器网络等通信场合的广泛应用,无线Ad Hoc网络成为当前研究的热点之一.针对无线AdHoc网络中AODV路由协议算法在网络拓扑结构改变后出现的性能缺陷,提出了一种改进后的AODV路由协议M_EAODV,通过设置多条备份路由来减少链路修复.仿真结果表明,改进后的AODV在分组传送成功率、平均端到端时延、路由开销等性能方面都得到了有效改善,能够在链路中断后迅速启用备份路由,更适应于拓扑结构变化快的网络环境. 相似文献
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多数Ad hoc网络路由研究聚焦于找到一条连接源和目的节点的路由,而没有考虑网络的QoS需求,一旦数据流量超过了网络所能承受的限度,数据流的传输质量将无从保证。提出了一种AOMDVQ(AOMDV Based on QoS)路由协议,在AOMDV基础上增加了带宽、时延、跳数和优先级等约束条件,使得在路由发起和路由维护阶段满足一定的QoS需求。仿真结果显示,AOMDVQ协议在高速移动状态下其数据包发送成功率、端到端时延等较AOMDV、MP-AOMDV协议有明显改进。 相似文献
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盘莉莉 《计算机工程与设计》2010,31(17)
路由协议对Ad hoc网络的性能影响很大.为了给"线性结构"Ad hoc网络找到合适的路由协议,研究了DSR和AODV协议的工作原理,对比分析DSR和AODV协议共性和区别.采用OPNET仿真"线性结构"网络环境,对比分析DSR协议和AODV协议的网络性能.仿真结果表明,DSR协议在分组投递率和吞吐量比AODV协议好,DSR协议的路由负荷比AODV稍差. 相似文献
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作者曾提出一个QoS路由和准入控制机制-QDSR,并且在小规模实时视频传输实验床上实现了这些方案。虽然QDSR的准入控制只保证每个节点有足够的可用带宽给准入的所有流使用,但并不保证每个流在较小的时间尺度上得到请求的带宽。为此,作者对QDSR的准入控制机制进行了改进并增加了流量控制机制,以满足实时应用的QoS需求。在NS2仿真环境中实现了QDSR以及对QDSR的改进。仿真结果表明,改进机制改善了QDSR的视频流的传输质量,较好地提高了视频流的吞吐率和投递率,减小了数据包的端到端延迟,并且能很好地满足包括视频传输在内的多种业务的传输需要。 相似文献
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Ying-Hong Wang 《Information Sciences》2006,176(2):161-185
Mobile Ad Hoc Networks (MANETs), which provide data networking without infrastructure, represent one kind of wireless networks. A MANET is a self-organizating and adaptive wireless network formed by the dynamic gathering of mobile nodes. Due to the mobility of mobile nodes, the topology of a MANET frequently changes and thus results in the disability of originally on-the-fly data transmission routes. The dynamic properties of MANETs are therefore challenging to protocol design. To cope with the intrinsic properties of MANETs, Dynamic Backup Routes Routing Protocol (DBR2P), a backup node mechanism for quick reconnection during link failures, is proposed in this paper. DBR2P is an on-demand routing protocol and it can set up many routes to reach a destination node in a given period. Even when a link fails, those routes from the source node to the destination node can be analyzed to obtain backup routes to sustain quick reconnection. The information of backup routes can be saved in a specific on-the-route node and enables backup routes to be found immediately in situation regarding disconnection. As a result, DBR2P could more thoroughly improve the quality of routing protocol than those proposed in the past. 相似文献
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《中国科学F辑(英文版)》2008,(9)
QoS supported MAC mechanism is a key issue for supporting QoS in wireless ad hoc networks. A new backoff algorithm,named RWBO BEB,was proposed previously to decrease the packet collision probability significantly. In this paper,it is explored how to make RWBO BEB support service differentiation in wireless ad hoc networks,and a novel proportional service differentiation algorithm,named p-RWBO,is proposed to allocate the wireless bandwidth according to the bandwidth ratio of each station. In p-RWBO,station n's walking probability(pw,n) is selected according to its allocated bandwidth ratio. An analytical model is proposed to analyze how to choose pw,n according to the bandwidth ratios of station n. The simulation results indicate that p-RWBO can differentiate services in terms of both bandwidth and delay. 相似文献
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移动自组织网络环境中,选择稳定路由可以提高数据传输率并能有效降低控制信息减少网络拥塞。根据无线自组网的特点,提出了一种新颖的基于信号强度评价链路稳定性的方法,并且基于此方法构建组播路由协议。协议中节点能够根据信号强度预估链路稳定性,选择稳定路由,及时发现修复即将断开的链路。仿真结果表明,协议可以明显提高数据传输率,并且控制开销较低。 相似文献
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A mobile ad hoc network (MANET) consists of a set of mobile hosts that can communicate with each other without the assistance of base stations. In MANETs, the high mobility of mobile nodes is a major reason for link failures. In this paper, we propose a stable weight-based on-demand routing protocol (SWORP) for MANETs. The proposed scheme uses the weight-based route strategy to select a stable route in order to enhance system performance. The weight of a route is decided by three factors: the route expiration time, the error count, and the hop count. Route discovery usually first finds multiple routes from the source node to the destination node. Then the path with the largest weight value for routing is selected. Simulation results show that the proposed SWORP outperforms DSR, AODV, and AODV-RFC, especially in a high mobility environment. 相似文献
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Kyungjun Kim Author Vitae 《Journal of Parallel and Distributed Computing》2011,71(3):335-342
Recently, one of the most critical issues in mobile ad hoc networks (MANETs) is providing quality of service (QoS) through routing, access/admission control, resource reservation, and mobility management. However, most existing solutions do not provide QoS effectively due to the interference arising from mobility. In this paper, we refer to interference as a quasi-exposed node problem. To solve this problem, a new algorithm, named a distributed channel assignment control, is proposed that focuses on performance enhancements related to QoS and mathematical analysis techniques for the channel bandwidth. This novel algorithm uses channel assignment control with a power control to reduce the negative effects induced by the quasi-exposed node problem, and then the channels are adaptively negotiated to allow communication in the interference region. The proposed algorithm has been evaluated via extensive simulations, and the results show that it can successfully guarantee QoS by maintaining good throughput, reducing control message overhead, and enhancing delay. 相似文献
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Compared with traditional networks, ad hoc networks possess many unique characteristics. For example, ad hoc networks can drop a packet due to network events other than buffer overflow. Unfortunately, the current layered network architecture makes it impossible to pass the information specific to one layer to other layers. As a result, if a packet is lost due to reasons other than buffer overflow, TCP adversely invokes its congestion control procedure. Similarly, the routing algorithm may misinterpret that a path is broken and adversely invoke the route recovery procedure.This study addresses the limitations of the current layered network architecture by adopting a cross-layer protocol design for TCP and routing algorithms in ad hoc networks. The objective of this approach is to enable the lower-layered ad hoc network to detect and differentiate all possible network events, including disconnections, channel errors, buffer overflow, and link-layer contention, that may cause packet loss. Using the information exploited by lower layers, the upper layer-3 routing algorithm, and the layer-4 TCP can take various actions according to the types of network events. Simulation results demonstrate that the combination of the cross-layer optimized TCP and routing algorithms can effectively improve the performance of TCP and DSR, regardless of whether it is in a stationary or a mobile ad hoc network. 相似文献