基于战术互联子网的路由协议性能仿真比较

本文对基于移动Ad Hoc网络的营连以下战术互联子网的网络环境以及应用业务类型特点进行了分析,通过OPNET仿真软件对AODV、DSR和OLSR路由协议在CBR、FrP和Voice三种不同业务类型下进行了仿真,分析了路由协议的平均端到端延时、平均吞吐量和路由控制开销.仿真结果表明,在营连以下战术互联子网在进行战场态势感知任务时,AODV和OLSR协议性能较好;而进行语音话务任务时,OLSR比其AODV和DSR协议性能好.     

一种基于信号强度的OLSR路由协议改进算法

借助接收分组时测得的信号强度,提出OLSR-PSSA(Pre-rerouting and Signal Strength A-ware OLSR)改进协议。为了建立和维护生存时间更长、链路更加健壮的路由,并加入预切换路由机制,来适应节点的移动和网络拓扑结构的频繁变化。OPNET仿真结果显示,与传统OLSR协议相比,OLSR-PSSA改进协议提升了传输成功率,增加了网络吞吐量。     

Ad Hoc网络中实现定位的OLSR协议研究

针对Ad Hoc网络中的节点位置估计和路由控制问题,在基于OLSR(最优链路状态路由)协议的基础上提出了一种能够同时实现路由和定位的综合协议OLSR-P(最优链路状态路由和定位)。该协议对OLSR协议进行了改进,能够将路由开销和定位有效结合,并对数据包结构进行改良,利用原协议的路由开销实现定位。仿真实验结果表明:OLSR-P协议不仅能够同时实现路由和定位,还能有效地控制开销。     

高动态Ad Hoc路由协议性能分析

Ad Hoc网络是一种没有固定设施的无线移动自组织网络,动态变化的拓扑结构对路由协议的性能有着重要影响。研究了动态源路由(DSR)协议、Ad Hoc按需距离矢量(AODV)路由协议和最优链路状态路由(OLSR)协议3种传统路由协议,利用OPNET软件作为仿真工具,设计了2种不同网络规模条件下空中飞行平台网络拓扑结构背景的高动态仿真方案,通过比较网络时延、归一化网络吞吐量、路由负载和数据传送成功率,分析了它们的性能。仿真结果表明,OLSR协议的综合性能优于其它协议,更适合于节点高速移动且网络拓扑结构频繁变化的Ad hoc网络,并为下一步研究打下基础。     

一种基于带宽估计的战术互联网TCP改进机制

无线的战术互联网通常面临复杂的电磁环境,高误码率、终端的频繁移动等恶劣的通信环境使得针对有线网络设计的TCP协议传榆性能急剧下降.针对战术互联网提出了一种基于带宽估计的TCP改进机制,该机制利用TCP确认帧携带的数据包到达时间来估算带宽,并用动态的低通滤波器来平滑带宽的估计值.在此基础上用带宽的估计值更新拥塞窗口,避免在发生链路错误时启动拥塞控制机制,由此提高TCP在战术互联网中的性能.实验结果表明,该算法能减少链路差错对TCP性能带来的影响,提高TCP在战术互联网上的传输性能.     

基于分布式时隙调度协议的战术互联网媒体访问控制技术

在分析现有移动无线网络TDMA时隙调度问题的基础上,根据战术互联网骨干网拓扑与业务需求,结合跳频电台的特点,提出了一种新的动态分布式TDMA时隙调度协议(DTSP),能够适应不同业务需求,支持单播、广播和组播.DTSP协议以无冲突的预留提高系统吞吐量,以渐增方式适应动态拓扑变化,动态调整的开销较小.最后,以DTSP时隙单播预留协议为例,进行了详细分析和复杂度计算.     

OLSR协议MPR覆盖度对网络性能的影响分析

路由协议是无线移动自组网（Mobile Ad Hoc Networks,MANETs）的关键技术之一。针对优化链路状态路由（Optimized Link SState Routing,OLSR）协议中的多点中继（Multipoint Relay,MPR）覆盖度对网络开销的影响进行了分析。OLSR协议与一般的链路状态协议相比,其采纳了MPR机制,一定程度上抑制了网络中广播控制信息的洪泛,从而降低了网络中的控制开销,但是这种机制是否影响到路由的鲁棒性是值得探讨的问题。基于此,设计了相应的MPR选择算法并进行仿真实验。结果表明,适当提高MPR覆盖度能加快路由的收敛。     

移动自组网OLSR路由协议研究

移动自组织网络具有移动、多跳和无中心等特点,可以快速灵活的组建网络,广泛应用在抗灾抢险、作战系统、科考探险等场景。使用MATLAB仿真软件,对最优链路状态路由协议进行仿真分析。实验结果表明,随着节点数目显著增加,OLSR协议路由的传输时间依然较短、传输跳数较少。因此,在规模较大、节点密集的移动自组网络中,使用OLSR协议能缩短的数据传输时间。     

基于MANET网络的服务协议

为了实现MANET网络的服务协议,提出了一种基于OLSR路由协议的MANET网络服务发布发现协议的设计方案,分析了OLSR路由协议的特点,根据MPR节点算法的特殊性,将服务消息通过MPR节点转发,通过主动模式和被动模式获取服务消息,实现服务发现.并设计了在OLSR路由协议下的服务协议机制.     

一种适用于战术条件下的自组织网路由协议

应用于战术条件下的自组织网络,其拓扑具有长期稳定而短期突变的特性;其流量具有不均衡性,中心节点的流量比重较大.针对战术无线网络的这种特性设计了一种混合式路由协议(HRP),协议为近端节点采用先应式协议维护路由而为远端节点采用反应式协议维护路由,对远端节点的路由请求采用OLSR协议的MPR思想,限制反应式协议的路由开销.并且,在近端拓扑变化频度超过门限值后,发起针对繁忙节点的路由发现请求,保持到繁忙节点的路由常新,从而提高了路由命中率.仿真结果表明,应用HRP协议后,无论其选路质量还是应用层业务的时延和吞吐量指标都优于DSR和ZRP协议.     

Improving mobile ad hoc network routing with satellite out‐of‐band signaling

Routing in mobile ad hoc networks is a complex task due to the mobility of the nodes and the constraints linked to a wireless multihop network (e.g., limited bandwidth, collisions, and bit errors). These adverse conditions impair not only data traffic but also routing signaling traffic, which feeds route computation. In this contribution, we propose to use satellite communications to help in the distribution of mobile ad hoc network routing signaling. The optimized link‐state routing (OLSR) is chosen among several routing protocols to be extended with satellite‐based signaling, yielding a version we call OLSR hybrid signaling (OLSR‐H). This new scheme is evaluated through simulations and yields improvements of approximately 10% in the data delivery ratio compared with a regular OLSR. This evaluation is conducted using two different network topology models, one being fit for representing forest firefighting operations. Copyright © 2013 John Wiley & Sons, Ltd.     

HOLSR: a hierarchical proactive routing mechanism for mobile ad hoc networks

This article reviews the hierarchical optimized link state routing (HOLSR) mechanism for heterogeneous mobile ad hoc networks. In this work a heterogeneous mobile ad hoc network is defined as a network of mobile nodes that are characterized by different communications capabilities, such as multiple radio interfaces. The article focuses on proposing the HOLSR protocol. The HOLSR mechanism is derived from the OLSR protocol; however, unlike OLSR, the HOLSR protocol takes advantage of different mobile node capabilities to reduce the routing control overhead in large heterogeneous ad hoc networks, thus improving the performance of the routing mechanism.     

An energy aware algorithm for OLSR clustering

One of the important aspects of a mobile ad hoc network (MANET) is the limitation of the amount of available energy and the network lifetime. The tremendous amount of using mobile nodes in wireless communication medium makes energy efficiency a fundamental requirement for MANETs. In this paper, we propose a novel energy aware clustering algorithm for the optimized link state routing (OLSR) routing protocol. This algorithm takes into account the node density and mobility and gives major improvements regarding the number of elected cluster heads. Our objective is to elect a reasonable number of cluster heads that will serve for hierarchical routing based on OLSR. The proposed algorithm aims to increase the network lifetime by considering the ad hoc residual energy while taking routing decisions. It also optimizes the delay of carried flows by adopting a selective forwarding approach based on a hierarchical routing model.     

Multipath optimized link state routing for mobile ad hoc networks

Multipath routing protocols for Mobile Ad hoc NETwork (MANET) address the problem of scalability, security (confidentiality and integrity), lifetime of networks, instability of wireless transmissions, and their adaptation to applications.Our protocol, called MultiPath OLSR (MP-OLSR), is a multipath routing protocol based on OLSR [1]. The Multipath Dijkstra Algorithm is proposed to obtain multiple paths. The algorithm gains great flexibility and extensibility by employing different link metrics and cost functions. In addition, route recovery and loop detection are implemented in MP-OLSR in order to improve quality of service regarding OLSR. The backward compatibility with OLSR based on IP source routing is also studied. Simulation based on Qualnet simulator is performed in different scenarios. A testbed is also set up to validate the protocol in real world. The results reveal that MP-OLSR is suitable for mobile, large and dense networks with large traffic, and could satisfy critical multimedia applications with high on time constraints.     

Chapar: A Persistent Overlay Event System for MANETs

In this paper, we present Chapar, an event system designed for mobile ad hoc networks that supports the publish/subscribe model as well as point–to–point and point–to–multipoint message delivery. Chapar supports event persistency to resist transient disconnections and network partitioning. Following a cross-layer approach, Chapar is designed as an overlay network that uses Multipoint Relays (MPRs) defined in OLSR, as distributed brokers to disseminate the events in a mobile network. Chapar handles topology changes as it uses the underlaying OLSR routing protocol for message delivery. The implementation performance is promising in the sense that no extra signaling is generated for mobility support and the generated overlay traffic is considerably less than the underlying routing protocol traffic.     

Routing in Large-Scale Wireless Mesh Networks Using Temperature Fields

Many wireless mesh networks are based on unicast routing protocols even though those protocols do not provide a particularly good fit for such scenarios. In this article, we report about an alternative routing paradigm, tailor-made for large multihop wireless mesh networks: field-based anycast routing. In particular, we present HEAT, a routing protocol based on this paradigm. In contrast to previous protocols, HEAT requires communication only between neighboring nodes. The underlying routing concept is a field similar to a temperature field in thermal physics. In extensive simulation experiments, we found that HEAT has excellent scalability properties due to a fully distributed implementation, and it provides much more robust routes than the unicast protocols, AODV and OLSR. As a consequence, in large-scale mobile scenarios, the packet delivery ratio with HEAT is more than two times higher, compared to AODV or OLSR. These promising results indicate that HEAT is suitable for large-scale wireless mesh networks that cover entire cities.     

Proficient link state routing in mobile ad hoc network-based deep Q-learning network optimized with chaotic bat swarm optimization algorithm

Mobile ad-hoc network (MANET) is a category of ad-hoc network that can be reconfigurable its network. MANETS are self-organized networks, that can use the wireless links to connect various networks via mobile nodes: but it consumes more energy and it also has routing problems. This is the major drawback of being connected with the MANET technology. Therefore, this study proposes a new protocol as deep Q-learning network optimized with chaotic bat swarm optimization algorithm (CBS)-based optimized link state routing (OLSR) (CBS-OLSR) for MANET. This protocol reduces MANET energy usage and adopts OLSR multi-point relay (MPR) technology. MANET's OLSR and the CBS algorithm utilize a similar method to locate the best optimum path from source to destination node. By embedding the new improved deep Q-learning and OLSR algorithms, both are used for optimizing the MPR sets selection, it can efficiently diminish the energy consumption in the network topology, but automatically increase the lifespan of the network. It also enhances the package delivery ratio and decreases end-to-end delay. The experimental outcomes prove that the proposed protocol is reliable and proficient that is appropriate for numerous MANET applications.     

WRE‐OLSR,a new scheme for enhancing the lifetime within ad hoc and wireless sensor networks

Within ad hoc and wireless sensor networks, communications are accomplished in dynamic environments with a random movement of mobile devices. Thus, routing protocols over these networks are an important concern to offer efficient network scalability, manage topology information, and prolong the network lifetime. Optimized link state routing (OLSR) is one of those routing protocols implemented in ad hoc and wireless sensor networks. Because of its proactive technique, routes between two nodes are established in a very short time, but it can spend a lot of resources for selecting the multipoint relays (MPRs: nodes responsible for routing data) and exchanging topology control information. Thus, nodes playing for a long time a role of MPR within networks implementing such protocol can rapidly exhaust their batteries, which create route failures and affect the network lifetime. Our main approach relies on analyzing this concern by introducing a new criterion that implements a combination between the residual energy of a node and its reachability in order to determine the optimal number of MPRs and sustain the network lifetime. Simulations performed illustrate obviously that our approach is more significant compared with the basic heuristic used by original OLSR to compute the MPR set of a node.