基于双线性对的Ad hoc网络主动秘密共享方案

针对现有的基于双线性对的安全机制都假设在整个Ad hoc网络生存期内系统都是安全的,而基于该假设的Ad hoc网络并不安全的问题。重新定义了Ad hoc网络的攻击者模型,对传统的主动秘密共享方案进行了扩充,提出了基于双线性对的Ad hoc网络主动秘密共享方案,周期性地更新系统私钥的影子和网络节点的私钥,以提高网络安全机制的安全性和鲁棒性,并对其安全性和鲁棒性进行证明。结论表明,基于双线性对的密码体制非常适合建立实用的、轻量级的Ad hoc网络的安全机制。     

TDMA体制下的移动自组织网时隙同步方法

在TDMA体制下的移动网状自组织网络中,为了解决网络时隙同步问题,提出了一种不依赖GPS授时的网络时隙互同步算法。各节点通过计算相邻节点的时隙偏差,通过加权计算并调整本节点的时隙位置,使网内各节点的时隙起始都调整到同一位置上,达到时隙的互同步。通过仿真和实验,分析并验证了移动自组织网络时隙互同步的收敛性能和抗干扰性能。     

一种新型的Ad Hoc网络分簇算法及其性能仿真

现存的Ad Hoc网络分簇算法大都只考虑影响网络性能的某个方面的因素，因此这些分簇算法的应用场合非常受限，本文在现存分簇算法的基础上设计了一种考虑多方面因素的新型分簇算法，可以在一定程度上改善网络的性能，并且具有较强的通用性，首先介绍了分簇算法提出的背景和一些相关的定义和假设，然后说明了几种现存的分簇算法的不足，接着重点分析了一种性能较好的分簇算法一自适应按需加权分簇算法，最后通过模拟对该分簇算法与其它映几种算法进行了性能比较和评价。     

一种基于辅助路由的拥塞自适应协议

针对现有多跳无线自组网路由协议以被动方式对拥塞进行处理,有可能导致更多的分组丢失、更长的时延和更大的网络开销问题,提出了一种基于辅助路由的拥塞自适应协议（congestion adaptive protocol based on aided-routing, CAPAR）。该协议以主动方式对拥塞进行处理,采取建立辅助路由的方法对发送给拥塞节点的业务流量进行分流,主动避免拥塞的发生,克服了以被动方式对拥塞进行处理所带来的不利影响。给出了CAPAR协议的建立过程,证明了CAPAR协议的正确性,并对其路由存储代价和路由更新代价进行了分析。结果表明,与其他按需路由协议相比,CAPAR减少了重新建立路由所带来的开销和时延,其路由更新代价明显降低。     

AD HOC网络中的一种QoS-AWARE多径路由协议

随着多媒体应用的不断发展,在Ad Hoc网络中提供QoS保证具有重要的意义.在研究节点拥塞、节点碰撞等本地信息对QoS路由影响的基础上,提出了一种在Ad Hoc网络中提供QoS保证的路由协议--基于本地信息的QoS-aware多径路由协议QAMR.该协议把带宽作为QoS参数,通过引入节点利用因子和路径利用因子来考虑可行路径处理能力问题和对业务的QoS保证.该协议的路由发现和路由维护算法是DSR协议的扩展.通过仿真和对比分析验证了QAMR协议无论在静态网络和动态网络,都具有很好的性能.     

BNE-based concurrent transmission considering channel quality and its PSO searching strategy in Ad Hoc networks

The paper proposes a decentralized concurrent transmission strategy in shared channels based on an incomplete information game in Ad Hoc networks.Based on the nodal channel quality,the game can work out a channel gain threshold,which decides the candidates for taking part in the concurrent transmission.The utility formula is made for maximizing the overall throughput based on channel quality variation.For an achievable Bayesian Nash equilibrium(BNE) solution,this paper further prices the selfish players in utility functions for attempting to improve the channel gain one-sidedly.Accordingly,this game allows each node to distributedly decide whether to transmit concurrently with others depending on the Nash equilibrium(NE).Besides,to make the proposed game practical,this paper next presents an efficient particle swarm optimization(PSO) model to fasten the otherwise very slow convergence procedure due to the large computational complexity.Numerical results show the proposed approach is feasible to increase concurrent transmission opportunities for active nodes and the convergence can be swiftly obtained with a few of iteration times by the proposed PSO algorithm.     

移动Ad Hoc网络的仿真框架

利用OPNET，提出一个通用的仿真框架用来测试不同的MAC层、网络层和节点移动性的移动AdHoc网络路由效率。在该层次整体框架下，可以设计不同的节点移动模式、媒体接入方法和路由方案，比较端到端统计量（端到端时延、吞吐量和效率），以筛选最有效、最合适的解决方案。     

Joint channel assignment and cross-layer routing protocol for multi-radio multi-channel Ad Hoc networks

To study multi-radio multi-channel (MR-MC) Ad Hoc networks based on 802.11, an efficient cross-layer routing protocol with the function of joint channel assignment, called joint channel assignment and cross-layer routing (JCACR), is presented. Firstly, this paper introduces a new concept called channel utilization percentage (CUP), which is for measuring the contention level of different channels in a node’s neighborhood, and deduces its optimal value for determining whether a channel is overloaded or not. Then, a metric parameter named channel selection metric (CSM) is designed, which actually reflects not only the channel status but also corresponding node’s capacity to seize it. JCACR evaluates channel assignment by CSM, performs a local optimization by assigning each node a channel with the smaller CSM value, and changes the working channel dynamically when the channel is overloaded. Therefore, the network load balancing can be achieved. In addition, simulation shows that, when compared with the protocol of weighted cumulative expected transfer time (WCETT), the new protocol can improve the network throughput and reduce the end-to-end average delay with fewer overheads.     

空分复用无线自组网跨层设计的NS2仿真研究

为了有效支持节点装备多天线的无线自组织网络的跨层协议设计。利用基于空分复用技术的物理层和接入层联合网络容量分析模型扩展NS2,构造了一个通用仿真平台,使其支持网络跨层空分复用接入协议。理论分析与仿真结果表明扩展后的NS2能够有效支持空分复用跨层协议设计。仿真证明对节点装备多天线的网络进行特别的跨层联合协议设计能够有效提高网络吞吐。     

Flooding attack and defence in Ad hoc networks

1 .INTRODUCTIONMobile Ad hoc Network is an autonomous system ofmobile nodes connected by wirelesslinks .It has sever-al salient characteristics ,such as Dynamic topologies ,Bandwidth-constrained,variable capacity links , Ener-gy-constrained operation,Li mited physical security[1].Due tothesefeatures ,mobile ad hoc networks are par-ticularly vulnerable to denial of service attackslaunchedthrough compromised node.In this paper , we present a new attack,theAd hoc Flooding Attack, which re…     

一种Ad Hoc网络组移动模型

战术互联网是Ad Hoc网络的主要应用，在该网络环境下，节点由于作战使命及建制的约束，移动节点常呈现出“组移动”的特征且组内节点通常分布在相对狭长的地带。针对战术互联网中移动节点的移动特征，提出了一种符合战术互联网环境的组移动模型：狭长的组移动模型（CGM：Confined Group Mobility），并从网络拓扑结构和对路由协议性能的影响两个方面与目前广泛采用的参考点组移动模型（RPGM：Refefence Point Group Mobility）进行了比较。仿真表明，不同的组移动模型对Ad Hoc网络的性能仿真将产生较大的影响。     

一种Ad Hoc网络信道接入退避算法及仿真分析

移动自组网络的应用环境以及其在商业上的潜在应用要求它支持QoS，高效合理的MAC协议对于保障Ad Hoc网络QoS具有重要的意义。在分析现有典型MAC协议及退避算法的基础上，提出了一种支特动态服务区分兼顾公平性的退避算法——服务区分动态退避（SDDB）算法。分析和仿真结果证明，与IEEE802．11等协议采用的退避算法相比，该算法在信道公平性和提供服务区分方面有较好的改善，并且在信道的吞吐量和提供服务区分、改善信道接入公平性之间能达到较好的折衷。     

自组网MRP移动模型节点的空间概率分布研究

MRP模型是一种具有记忆特性的移动模型;与Ad Hoc网络其它移动模型相比,它在节点移动的稳定性和真实性方面具有显著优势。对MRP模型移动节点的空间概率分布进行了深入研究,得出了一维区域和二维区域上的节点空间概率分布,并进一步总结了概率参数q值和移动步数对节点空间概率分布的影响,最后通过仿真对所得出的模型性质进行了验证。结果表明,移动步数一定,q值越大,节点越趋向于在初始位置周围运动;q值一定,移动步数越大,节点空间分布越均匀。     

Multi-agent cooperative intrusion response in mobile adhoc networks

The nature of adhoc networks makes them vulnerable to security attacks. Many security technologies such as intrusion prevention and intrusion detection are passive in response to intrusions in that their countermeasures are only to protect the networks, and there is no automated network-wide counteraction against detected intrusions. the architecture of cooperation intrusion response based multi-agent is propose. The architecture is composed of mobile agents. Monitor agent resides on every node and monitors its neighbor nodes. Decision agent collects information from monitor nodes and detects an intrusion by security policies. When an intruder is found in the architecture, the block agents will get to the neighbor nodes of the intruder and form the mobile firewall to isolate the intruder. In the end, we evaluate it by simulation.     

一种Ad Hoc网络信道接入排队退避公平算法

移动Ad hoc网络是一种特殊的无固定控制中心的多跳网络。由于其特殊性，传统的CSMA协议直接应用在Ad hoc网络中会带来隐终端、暴露终端和公平性问题。本文基于Ad hoc网络信道接入层已有退避算法，提出了一种新型排队退避公平算法。分析与仿真结果表明，与IEEE802．11标准的BEB算法和其它算法相比，本文算法更为简单实用，且对于合适的参数取值，本文算法能有效地改善信道接入的不公平性，并能在信道吞吐量的下降和信道接入公平性的改善之间达到一个较好的折衷。     

MANET双层群节点移动模型设计与研究

在移动Ad hoc网络仿真中,节点移动模型直接决定了网络的拓扑结构,进而影响网络性能的评估."参考点群移动模型"群内部节点以一个逻辑中心为参考随机运动,而现实场景中,节点群运动时经常呈现一个群有多个逻辑中心的特点.由此提出了一种"双层群移动模型",并从物理链路和路由协议两个层面与其它移动模型进行仿真比较.仿真结果表明,该模型更能反映出具有双层性的群移动场景中网络的拓扑变化,更适合该种场景下移动Ad hoc网络仿真研究.     

Ad Hoc网络中一种基于邻节点活跃度的自适应退避算法

基于无线AdHoc网络中信道共享的特性,通常采用具有退避机制的MAC接入协议。由于网络节点的各邻居节点在前一段时间的活跃状态在一定程度上反映了网络的繁忙状况,活跃的邻居节点越多,表示信道竞争越激烈,网络越繁忙,反之网络比较空闲。据此,提出了一种基于邻居节点活跃状态的时延退避算法,根据邻居节点活跃数量自适应地调整时延退避窗口,从而提高了网络吞吐率。     

移动Ad hoc网络分布式并行接入控制协议分析

通过对无线令牌环协议(WTRP)进行改进,提出了一种新的具有QoS保障且无竞争的分布式并行接入协议(DP-BSCP)。采用嵌入Markov链和概率母函数的分析方法,用限定服务规则进行系统建模,在系统模型的基础上得到了系统的平均排队队长以及平均等待时间的解析结果,同时也分析了不同优先级队列间的性能关系。理论分析和仿真结果是一致的,表明该协议的平均排队等待延迟和平均等待队列长度均比WTRP有很大降低;对不同优先级的数据包均有良好的适应性,满足不同优先级的性能需求且稳定性大大增强,更加适用于多业务的综合服务系统。     

Distributed intrusion detection for mobile ad hoc networks

Mobile ad hoc networking(MANET)has become an exciting and important technology in recent years,because of the rapid proliferation of wireless devices.Mobile ad hoc networks is highly vulnerable to attacks due to the open medium,dynamically changing network topology,cooperative algorithms,and lack of centralized monitoring and management point.The traditional way of protecting networks with firewalls and encryption software is no longer sufficient and effective for those features.A distributed intrusion detection approach based on timed automata is given.A cluster-based detection scheme is presented,where periodically a node is elected as the monitor node for a cluster.These monitor nodes can not only make local intrusion detection decisions,but also cooperatively take part in global intrusion detection.And then the timed automata is constructed by the way of manually abstracting the correct behaviours of the node according to the routing protocol of dynamic source routing(DSR).The monitor nodes can verify the behaviour of every nodes by timed automata,and validly detect real-time attacks without signatures of intrusion or trained data.Compared with the architecture where each node is its own IDS agent,the approach is much more efficient while maintaining the same level of effectiveness.Finally,the intrusion detection method is evaluated through simulation experiments.     

Link reliability based hybrid routing for tactical mobile ad hoc network

Tactical mobile ad hoc network （MANET） is a collection of mobile nodes forming a temporary network, without the aid of pre-established network infrastructure. The routing protocol has a crucial impact on the network performance in battlefields. Link reliability based hybrid routing （LRHR） is proposed, which is a novel hybrid routing protocol, for tactical MANET. Contrary to the traditional single path routing strategy, multiple paths are established between a pair of source-destination nodes. In the hybrid routing strategy, the rate of topological change provides a natural mechanism for switching dynamically between table-driven and on-demand routing. The simulation results indicate that the performances of the protocol in packet delivery ratio, routing overhead, and average end-to-end delay are better than the conventional routing protocol.