Cooperative Caching Strategy in Mobile Ad Hoc Networks Based on Clusters

In this paper, we present a scheme, called Cluster Cooperative (CC) for caching in mobile ad hoc networks. In CC scheme, the network topology is partitioned into non-overlapping clusters based on the physical network proximity. For a local cache miss, each client looks for data item in the cluster. If no client inside the cluster has cached the requested item, the request is forwarded to the next client on the routing path towards server. A cache replacement policy, called Least Utility Value with Migration (LUV-Mi) is developed. The LUV-Mi policy is suitable for cooperation in clustered ad hoc environment because it considers the performance of an entire cluster along with the performance of local client. Simulation experiments show that CC caching mechanism achieves significant improvements in cache hit ratio and average query latency in comparison with other caching strategies.     

Ad hoc网络中移动骨干网的建立和维护

Ad hoc网络中的移动骨干网的建立和维护是一项复杂的工作.本文首先比较了两种不同类型的骨干网络,然后说明了移动骨干网络的构造目标,接着重点对Ad hoc网络中移动骨干网的建立和维护过程进行了详细的论述,最后对全文进行了小结.     

移动Ad hoc网络中基于自适应策略的稳定链路选择算法

该文提出了一种基于自适应策略的稳定链路选择算法,定义了稳定邻居度量和本地运动度量两种稳定测度。在此基础上,通过引入模糊隶属度函数得出稳定测度的重要性权值,利用重要性加权的方法即可根据网络状况自适应地得到链路的稳定概率,从而为选择最稳定链路及路由提供依据。仿真结果表明该算法能很好地适应当前的网络状况,明显优于基于LF因子和基于剩余生命时间的链路选择算法,稳定性能显著提高。     

移动自组网中一种基于业务的拓扑控制算法

拓扑控制的实现途径是调节网络中每个节点的传输功率,而其所优化的网络指标有所差别,通常是减少节点的功率消耗以延长网络的生存时间。现有的拓扑控制算法关注在保证连通性的情况下优化网络的功率使用,较少考虑业务QoS指标对网络连接性要求。一种基于业务需求的拓扑控制算法被提出,在拓扑控制算法中引入业务QoS指标,如时延、带宽等。通过理论分析和计算机仿真结果表明,该算法对有QoS要求的业务有较好的支持。     

An Adaptive and Predictive Security Model for Mobile Ad hoc Networks

Mobile ad hoc networks are infrastructure-free, pervasive and ubiquitous in nature, without any centralized authority. These unique characteristics coupled with the growing concerns for security attacks demand an immediate solution for securing the ad hoc network, prior to its full-fledged deployment in commercial and military applications. So far, most of the research in mobile ad hoc networks has been primarily focused on routing and mobility aspects rather than securing the ad hoc networks themselves. Due to ever increasing security threats, there is a need to develop schemes, algorithms, and protocols for a secured ad hoc network infrastructure. To realize this objective, we have proposed a practical and effective security model for mobile ad hoc networks. The proposed predictive security model is designed using a fuzzy feedback control approach. The model is based on identifying critical network parameters that are affected by various types of attacks and it continuously monitors those parameters. Once we measure the relative change in these parameter values, we could detect the type of attack accurately and protect the system, without compromising its effectiveness. Experimental results of the model simulated for selected packet mistreatment attacks and routing attacks are very promising.     

用移动IP实现移动Ad hoc网与Internet的互联

移动IP是一种简单可扩展的全球Internet移动解决方案。本文介绍了移动IP和移动Ad hoc网络的融合技术,以实现移动Ad hoc网络与Internet的互联。     

基于重复博弈的Ad hoc网络合作转发模型

针对噪音环境下的Ad hoc网络合作问题,运用不完美信息重复博弈模型分析节点之间的交互过程,使用贝尔曼方程构造满足序贯均衡的合作激励机制。对于该机制,节点间无需交换观察信息,节省了节点能量和网络负担。与已有的序贯均衡策略相比,该机制避免使用对观测误差敏感的触发策略,提高了不完美信息环境下网络的合作率和节点的平均收益。仿真结果表明,使用贝尔曼方程构造的序贯均衡策略既提高了网络的合作率,又有很好的适应性。     

Name‐Based Autoconfiguration for Mobile Ad hoc Networks

In a mobile ad hoc network, difficulties exist in supporting address autoconfiguration and naming resolution due to the lack of centralized servers. This letter presents a novel approach, called name‐based autoconfiguration (NBA), which uses host names to determine IP addresses and provides address autoconfiguration and name resolution as a single protocol.     

Cluster-Based Autoconfiguration for Mobile Ad hoc Networks

IP address autoconfiguration of mobile nodes is highly desirable in the practical usage of most mobile ad hoc networks (MANETs). This paper proposes cluster-based autoconfiguration, a novel approach for the efficient address autoconfiguration of MANETs. The cluster structure derived from clustering techniques is used to manage address assignment and conflict resolution. By introducing the concept of virtual address agents (AAs), the proposed approach can be applicable to many existing clustering protocols. Finally, analysis and simulation demonstrate that the proposed scheme outperforms the previous autoconfiguration approaches.

Energy Efficient Multi-hop Cooperative Transmission Protocol for Large Scale Mobile Ad hoc Networks

A great advancement has been made in intelligent transportation system and communication technologies in order to exchange secure information between automobiles, facilities provider have led an frame over road network. The intelligent transportation system provides an efficient traffic system for drivers, so that there must be less risk to users. In order to design a secure communication protocol among V & V and V & I is a challenging problem. In order to reduce the chance of attacks and increase privacy level, crypto graphic tools provides the feasible solution. In this paper, we proposed pseudonym changing strategy with mix zones (1) Anonymous authentication: the message should be authenticated by issuer due to mix zone and cryptographic tools secure message without any attack. (2) Privacy: Communication contents are confidential due to encrypted messages during communications also improving the scalability through address configuration scheme to reduce computational cost. (3) Efficiency: low storage requirements, The velocity and distance factors may also consider secure measurement, message delivery, overhead and coverage,packet delivery rate, reduce latency and overhead not only by computation cost and time but also compared our scheme, fast delivery rate, low latency and maximum coverage in order to enhance privacy against malicious attacks.

     

移动Ad hoc网络的QoS路由实现机制

随着实时多媒体业务向移动Adhoc网络的引入,如何为移动Adhoc网络提供服务质量保证成为当前研究的热点。本文介绍了为移动Adhoc网络提供QoS路由的三种实现机制:MAC层的TDMA资源管理、普通的QoS测量、CDMA的不同传输之间的冲突避免。     

Stimulating Node Cooperation in Mobile Ad hoc Networks

Mobile Ad hoc Networks (MANETs) rely on the cooperation of nodes for packet routing and forwarding. Much of the existing work in MANETs assume that mobile nodes (possibly owned by selfish users) will follow prescribed protocols without deviation. However, a user may misbehave due to several advantages resulting from noncooperation, the most obvious being power saving. As such, the network availability is severely endangered. Hence, enforcing the cooperation among nodes becomes a very important issue. Several different approaches have been developed to detect non-cooperative nodes or deal with the non-cooperative behavior of mobile nodes in MANETs. These protocols are first surveyed in details in this paper. It is found that the proposed approaches have several concerns that prevent them from really enforcing the node cooperation in MANETs. Thus, a new scheme that can stimulate and also enforce nodes to cooperate in a selfish ad hoc environment is presented. We also present a mechanism to detect and exclude potential threats of selfish mobile nodes. The simulation results indicate that by using the proposed scheme, MANETs can be robust against nodes’ misbehaving and the performance of the network is enhanced many folds when compared to other existing schemes.

三维移动Ad hoc网络链路动态性研究

3维移动Ad hoc网络(3-D MANET)是一种网络场景分布于3维空间的移动Ad hoc网络。链路动态性分析是研究3-D MANET的一项基础性工作,其结论可作为网络协议设计的基础。该文基于CV(Constant Velocity)移动模型,从概率模型的角度推导出了链路寿命期望和分布的数学表达式,并通过仿真实验进行了验证,表明了理论计算结果的正确性。结论对3-D MANET的研究和应用具有一定的参考价值。     

移动Ad hoc网络基于干扰和连通度的路由协议

移动Ad hoc网络中,节点随机移动会引起通信链路频繁断开,从而导致路由失效,带来大量的路由重建与路由发现,耗费了有限的网络资源。传统按需路由中,采用简单的洪泛进行路由发现,路由请求包的盲目转发会带来大量不必要的冗余转发,造成广播风暴问题。此外,大量的数据包同时发送也会对彼此的传输造成干扰,增加数据包冲突概率。针对这种情况,本文提出一种基于干扰和连通度的路由协议,该协议结合节点的连通度和潜在干扰设计转发概率,不仅减少了路由请求包的传播范围,还减少了路由请求包的冲突概率,提高了传输成功率。仿真结果表明,本文设计的方案在减少路由开销的同时,有效提高了数据包投递率,从而提高了路由性能。     

基于路径分段的MANET自适应多径路由协议

采用多径路由机制能够有效保证Ad hoc网络数据包传输成功概率,提高网络可靠性。该文在路径数量分析的基础上,根据分组丢弃概率门限判决方法,提出了基于路径分段的自适应多径路由协议。节点采用预先设定的门限值判定链路状态,并且根据网络当前的拓扑状态自适应地选择中继节点,建立路径分段的多径路由。仿真结果表明,该机制在合理利用网络资源的同时能够有效保障数据包的可靠传输,更加适用于状态时变的Ad hoc网络。     

New Approaches to Routing in Mobile Ad hoc Networks

Worldwide Interoperability for Microwave Access (Wimax) is power station through which mobile network, commonly known as A Mobile Ad-hoc Network (MANET) is used by the people. A MANET can be described as an infrastructure-less and self-configure network with autonomous nodes. Participated nodes in MANETs move through the network constantly causing frequent topology changes. Designing suitable routing protocols to handle the dynamic topology changes in MANETs can enhance the performance of the network. In this regard, this paper proposes four algorithms for the routing problem in MANETs. First, we propose a new method called Classical Logic-based Routing Algorithm for the routing problem in MANETs. Second is a routing algorithm named Fuzzy Logic-based Routing Algorithm (FLRA). Third, a Reinforcement Learning-based Routing Algorithm is proposed to construct optimal paths in MANETs. Finally, a fuzzy logic-based method is accompanied with reinforcement learning to mitigate existing problems in FLRA. This algorithm is called Reinforcement Learning and Fuzzy Logic-based (RLFLRA) Routing Algorithm. Our proposed approaches can be deployed in dynamic environments and take four important fuzzy variables such as available bandwidth, residual energy, mobility speed, and hop-count into consideration. Simulation results depict that learning process has a great impact on network performance and RLFLRA outperforms other proposed algorithms in terms of throughput, route discovery time, packet delivery ratio, network access delay, and hop-count.

     

基于自适应蜂鸟算法的飞行自组网拓扑优化

针对飞行自组网(FANET)中无人机(UAVs)快速移动造成的网络拓扑管理困难问题,考虑实际场景中无人机位置变化引起的可用信道差异,该文提出一种自适应蜂鸟算法对网络拓扑进行优化。首先,建立一个针对分簇结构的无人机拓扑模型,并且形成一个以最小化簇数量、负载偏差和簇移动度为目标的优化问题。其次,通过调节人工蜂鸟的觅食动作、加入扰动变异的方式,提出寻优能力更强的自适应蜂鸟算法(ADHA)。然后,设计合理的蜂鸟个体编码方式,将拓扑优化的决策过程转化为自适应蜂鸟算法的寻优过程。最后,通过仿真验证所提算法的收敛性,并与基于其他群智能优化算法的拓扑优化方法进行对比。实验结果表明,所提算法得到的拓扑优化策略不仅能够有效减少网络拓扑的簇数量,而且能够得到负载均衡、结构稳定的簇群。     

基于位置信息的大区域移动自组网MAC协议

针对大区域移动自组网提出一种基于位置信息的MAC协议(PB-MAC).该协议采用CSMMCA方式来交换控制信息,采用TDMA方式进行数据业务传输,并在位置信息的辅助下对数据传输进行时隙调整.仿真结果表明,PB-MAC能有效提高网络吞吐量,提供确定的延时上界,并使网络保持较好的可扩展性.     

Securing Mobile Ad hoc Networks — A Motivational Approach

Mobile ad hoc networks rely on the co-operation of devices that route for each other. This immediately presents security problems. Each device's data passes through the not so friendly hands of other devices. Forwarding devices must use their processing power and battery power to route packets for others. When bandwidth is limited they must also use bandwidth that they might want to use for themselves. These are not great issues with the first incarnations of ad hoc networks — military systems or others where all the devices are owned by a single organisation. However, if ad hoc networks are to be generally deployed and become an alternative or adjunct to future cellular systems, then ways to encourage co-operation are required. This revised version was published online in July 2006 with corrections to the Cover Date.     

A Position Based Speed Adaptive Dissemination approach for Vehicular Ad hoc Networks

Wireless Personal Communications - Vehicular Ad hoc Networks (VANETs) being a vital component of Intelligent Transport System (ITS), is getting due attention from the research community....