无线传感器网络中恶意软件传播研究

从平面无线传感器网络的拓扑结构、无线共享通信及安全机制等固有特征出发,对无线传感器网络上的恶意软件传播动力学进行研究。首先,使用随机几何图建立平面无线传感器网络模型;然后,基于元胞自动机理论建立恶意软件SI（Susceptible—Infected）传播模型,该模型充分考虑无线传感器网络固有特征和传播特征,模型建立引入MAC机制和随机密钥预分布方案。分析和仿真表明,无线传感器网络的空间局域化结构特征、无线信道共享机制和安全管理应用主导了传播增长效果,限制了恶意软件传播速度,降低了在无线传感器网络中大规模流行恶意软件的风险。文中提出的模型能够描述无线传感器网络中恶意软件传播行为,为建立无线传感器网络安全防御机制提供了基础。     

面向无线ad hoc网络的一种平面t-支撑图

拓扑控制算法的目标是为无线ad hoc网络确定合适的底层拓扑。在无线ad hoc网络中，几何路由协议是一类重要的路由协议，为了保证消息转发的可达性和限制路由长度，它要求底层拓扑满足连通性、平面性和稀疏性，并且是原拓扑的t-支撑图。本文提出了一种新的几何结构AUDel图，并提出了两种低通信开销的构造AUDel图的局部拓扑控制算法。理论分析表明，AUDel图满足上述要求，我们提出的拓扑控制算法的通信歼销小于其它构造平面t-支撑图的拓扑控制算法。模拟实验验证了以上结论。     

高速公路场景中车用自组织网络的节点度

该文基于大尺度路径损耗无线传播模型将高速公路场景中的车用自组织网络(VANET)建模为几何随机图,提出了VANET有效组网面积的概念,分析说明了VANET的准线性拓扑特点,并基于交通流理论关于自由流条件下的车头时距分布,推导得出了无线传输范围内至少存在k个邻居的概率计算方法。实验结果表明:该文提出的概率描述思想是一种适合计算高速公路场景中车辆网络节点度的有效方法。     

移动无线传感网恶意数据包传播随机模型

该文基于随机元胞自动机理论研究移动无线传感器网络中恶意数据包的传播行为.依据移动无线传感器网络的信息扩散机制,设计节点移动模型、无线信道分配算法、信号干扰模型和恶意数据包传播模型,定义移动传感器网络环境下的元胞空间、元胞邻域、元胞状态以及状态转换规则,提出移动无线传感器网络中恶意数据包传播的随机元胞自动机模型,研究在不确定环境下恶意数据包传播的时空特征.研究结果表明该模型能够有效预测恶意数据包传播的趋势和空间分布状态,有效克服基于马尔科夫随机场理论、常微分方程或差分方程建立的恶意数据包传播模型而无法描述恶意数据包传播的空间分布状态的不足.     

3G无线传感器网络在智能配电网的应用研究

本文提出一种基于3G通信的无线传感器网络(简称3G无线传感器网络)在智能配电网中的应用模型,介绍了3G无线传感器网络的概念与应用特点,在分析配电网络结构的基础上给出了3G无线传感器网络的拓扑结构,提出了带冗余的混合路由模式,最后给出了配电网中3G传感器节点的设计.     

建筑用位置固定节点的无线传感器网络的设计

针对智能建筑中无线传感器网络物理位置固定的特点,设计了一种通讯协议简单的无线传感器网络。以建筑物的层高、纵向房间号和横向房间编号为已知信息对,无线传感器的地址编码,设计三维立方模型,使得每个节点可获得整个网络的拓扑信息。最后通过在智能建筑照明中的应用得以验证。     

一种能耗鲁棒性权衡的3D-WSN拓扑控制算法

该文针对3维无线传感器网络(3D-WSN)需兼顾能耗与鲁棒性的问题,建立了能耗鲁棒性权衡模型,利用Lyapunov稳定性理论证明了稳定平衡解的存在。进而提出了一种基于该模型的拓扑控制算法(TCA-TM),获得了3维无线传感器网络的优化拓扑。实验结果表明,该拓扑结构不仅能够满足网络鲁棒性要求,还能有效地均衡网络能耗,延长网络生命期。     

可充电无线传感器网络动态拓扑问题研究

在可充电无线传感器网络中的能量补给设备兼任数据采集设备的情况下,提出了可充电无线传感器网络时变动态拓扑模型,并在此基础上根据最大化能量补给设备驻站时间比为目标提出了最优化问题。通过分析不同时刻不同传感器节点和无线能量补给/数据采集设备的工作情况及需要遵循的约束条件,得到与原问题具有等优性的多状态线性规划问题。求解该优化问题,获得可充电无线传感器网络动态拓扑下的周期动态路由和无线能量补给/数据采集设备的工作策略。与之前的研究成果相比,优化目标值均有20%以上的提升。     

基于拓扑控制的无线传感器网络节点负载均衡策略

无线传感器网络已成为当今的一个研究热点,由于无线传感器网络是一个能量受限网络,需要采取措施延长网络的正常使用寿命,负载均衡策略正是延长网络生命期的重要手段.本文介绍无线传感器网络中的节点负载问题,提出了一种基于拓扑控制的无线传感器网络节点负载均衡策略,有助于延长无线传感器网络的使用寿命.     

基于多簇点简化的K容错能量均衡拓扑控制方案

针对异构监测传感器网络结构,设计了一个容错拓扑控制方案,在可以减少网络冗余的同时,兼顾了网络的稳定性,并且保证生成拓扑具有最小的能量消耗。该方案首先将异构监测传感器网络简化为同构传感器网络以简化计算,然后根据节点的位置信息,建立各监测节点到簇节点的能量消耗最小,并且可以保证K容错的K连通子图。该方案在保证传感器网络K连通的前提下,可以最大限度减少传感器网络中的冗余路径,且可以较好地均衡无线传感器网络能耗,延长网络生命周期。     

Product Multicommodity Flow in Wireless Networks

We provide a tight approximate characterization of the n-dimensional product multicommodity flow (PMF) region for a wireless network of n nodes. Separate characterizations in terms of the spectral properties of appropriate network graphs are obtained in both an information-theoretic sense and for a combinatorial interference model (e.g., protocol model). These provide an inner approximation to the n ²-dimensional capacity region. Our results hold for general node distributions, traffic models, and channel fading models. We first establish that the random source-destination model assumed in many previous results on capacity scaling laws, is essentially a one-dimensional approximation to the capacity region and a special case of PMF. We then build on the results for a wireline network (graph) that relate PMF to its spectral (or cut) properties. Specifically, for a combinatorial interference model given by a network graph and a conflict graph, we relate the PMF to the spectral properties of the underlying graphs resulting in simple computational upper and lower bounds. These results show that the 1/radicn scaling law obtained by Gupta and Kumar for a geometric random network can be explained in terms of the scaling law of the conductance of a geometric random graph. For the more interesting random fading model with additive white Gaussian noise (AWGN), we show that the scaling laws for PMF can again be tightly characterized by the spectral properties of appropriately defined graphs-such a characterization for general wireless networks has not been available before. As an implication, we obtain computationally efficient upper and lower bounds on the PMF for any wireless network with a guaranteed approximation factor.     

Enhancing Efficiency of Node Compromise Attacks in Vehicular Ad-hoc Networks Using Connected Dominating Set

In the node compromise attack, the adversary physically captures nodes and extracts the cryptographic keys from the memories, which destroys the security, reliability and confidentiality of the networks. Due to the dynamical network topology, designing an efficient node compromise attack algorithm is challenging, because it is difficult to model the attack or to enhance the attacking efficiency. In this paper, a general algorithm for modeling the node compromise attack in VANET is proposed, which promotes the attacking efficiency by destroying the network backbone. The backbone is constructed using the connected dominating set of the network, which has relevant to the intermeeting time between the vehicles. Then two attacking algorithms are proposed based on the general model, which destroy the network in a centralized and distributed version while maximizing the destructiveness. Simulations are conducted to show the advantages of our scheme. Simulation results reveal that our scheme enhances the attacking efficiency in different mobility models and different applications, which is suitable for modeling the node compromise attack in VANET. At last, discussions are presented to the illustrate the influences of the characteristics to the attacking efficiency with respect to vehicle speed, communication range and key sharing probability.     

邻近信息约束下的随机异构无线传感器网络节点调度算法

针对高密度部署的随机异构传感器网络内部存在的覆盖冗余问题,该文提出一种随机异构无线传感器网络的节点调度算法(NSSH)。在网络原型拓扑的支撑下构建Delaunary三角剖分,规划出节点进行本地化调度的局部工作子集。通过折中与邻近节点的空外接圆半径,完成对感知半径的独立配置;引入几何线、面概念,利用重叠面积和有效约束圆弧完成对灰、黑色节点的分类识别,使得节点仅依赖本地及邻居信息进行半径调整和冗余休眠。仿真结果表明,NSSH能以低复杂度的代价,近似追平贪婪算法的去冗余性能,并表现出了对网络规模、异构跨度和参数配置的低敏感性。     

Cost-effective WDM backbone network design with OXCs of different bandwidth granularities

We investigate the design of a WDM backbone network with optical cross-connects (OXCs) of different switching granularities to reduce the network-wide OXC port cost. We enhance our proposed graph model (Zhu, H. et al., IEEE/ACM Trans. Networking, vol.11, p.285-99, 2003), and the extended graph model can represent different node architectures in which a node may have multiple OXCs with different switching granularities simultaneously. Based on this model, we propose a provisioning algorithm for a single connection and a framework for network design, which can intelligently determine the type of OXCs at each node according to the traffic so that the benefit of different types of OXCs can be utilized. Numerical examples are presented showing that granularity-heterogeneous networks are more cost-effective than granularity-homogeneous networks.     

On the capacity of network coding for random networks

We study the maximum flow possible between a single-source and multiple terminals in a weighted random graph (modeling a wired network) and a weighted random geometric graph (modeling an ad-hoc wireless network) using network coding. For the weighted random graph model, we show that the network coding capacity concentrates around the expected number of nearest neighbors of the source and the terminals. Specifically, for a network with a single source, l terminals, and n relay nodes such that the link capacities between any two nodes is independent and identically distributed (i.i.d.) /spl sim/X, the maximum flow between the source and the terminals is approximately nE[X] with high probability. For the weighted random geometric graph model where two nodes are connected if they are within a certain distance of each other we show that with high probability the network coding capacity is greater than or equal to the expected number of nearest neighbors of the node with the least coverage area.     

On the improvement of network resource utilization efficiency for the establishment of static dependable connections in SRLG-constrained WDM translucent networks

In this paper, we investigate the problem of establishing static connections with fault-tolerant requirements, also known as dependable connections, taking into account quality of transmission constraints. To the best of our knowledge, this is the first study that tackles the aforementioned problem under shared risk link group (SRLG) constraints in translucent WDM optical mesh networks where typically a set of strategically localized network nodes are equipped with regeneration capability to overcome physical-layer impairment effects. A novel cross-layer heuristic approach is introduced to solve the problem for an heterogeneous networked scenario relying on a cost-effective two-stage protection procedure which combines the well-known path protection and partial path protection schemes in order to ensure instantaneous recovery from any SRLG-failure event. The proposed heuristic integrates a generic auxiliary graph model that incorporates various network heterogeneity factors such as the number of transceivers at each network node, the number of wavelengths on each fiber link, and the regeneration capability of each node, represented by different edges in the constructed graph. Moreover, the integrated auxiliary graph can be applied efficiently to model either single- or mixed-line-rate translucent WDM optical networks wherein different modulation formats are employed in order to support the transmission at different line rates. Our solution approach aims at maximizing the total number of accommodated requests by reducing network resource consumption through the simultaneous use of the backup–backup and primary–backup multiplexing techniques. We, here, present extended versions of these two techniques that generalize the sharing concept to some other important node resources—specifically, regeneration equipments which constitute the major cost factor in optical transport networks—in addition to link resources (i.e., wavelength channels). As far as we know, this is the first attempt to deploy simultaneously generalized versions of the backup–backup and primary–backup multiplexing techniques when considering static traffic patterns without compromising the 100 % fault-recoverability guarantee. The performances of the proposed heuristic are evaluated and discussed through extensive numerical experiments carried out on different network topologies. Significant improvements are demonstrated, either in terms of network blocking performance or in terms of resource utilization efficiency, in comparison with previously proposed approaches.     

Dynamics of a rumor‐spreading model with diversity of configurations in scale‐free networks

In this paper, we propose a new rumor‐spreading model, which is a variant of the susceptible–exposed–infectious–removed epidemic model. We consider the influences of the diversity of configurations as a defense strategy to diminish the damage brought by rumor diffusion. The diversity of configuration can be found in different instant messengers or social networks. Moreover, we apply two kinds of the rumor immunization strategies such as random immunization and targeted immunization and show that targeted immunization is better than random immunization for rumor‐spreading control in scale‐free networks. We carry out the systematic analysis of the model and study the local and global stability of rumor‐free equilibrium. In the proposed model, we introduce two new states, namely, hibernator and stifler2, to study dynamical behaviors of the model. The proposed model combines both targeted immunization and diversity of configuration to prevent rumor spreading. By numerical simulations, we indicate that our model is appreciably better than other models in terms of declining the rumor diffusion speed. Furthermore, we investigate many related dynamic properties to make the result more complete. Simulation results show the effect of different parameters on the rumor diffusion in scale‐free networks; meanwhile, numerical simulations confirm the theoretical solution. Copyright © 2015 John Wiley & Sons, Ltd.     

Secure Localization Technology Based on Dynamic Trust Management in Wireless Sensor Networks

Wireless sensor networks have critical applications in various fields,and the algorithm of their se-cure localization has become a vital technology to support a network.In the light of the self-organization,random deployment and dynamic topology,the localization process is vulnerable to various kinds of malicious attacks.The model of dynamic trust management for a given node is proposed to deal with security concerns in wireless sensor networks.The trust computation is divided into three stages,which are the stage of trust initialization,trust establishment,and trust evolution.The initial value of a global trust relationship is established through a corresponding global trust relation graph in the initial stage of trust.The trust value of each node is calculated by the attribute value in the stage of trust establishment.In the evolution of trust,the iterative process of trust value is accelerated via the finite state machine.Compared with the existing wireless sensor networks,simulation results show that the proposed security localization technology method can resist many kinds of attacks with low communication and time consumption.