改进的可靠信道路由算法在认知无线电Ad-hoc网络中的应用

针对认知无线电网络中传统路由可靠性较低的问题,提出了一种改进的可靠信道路由算法(Improved reliable channel routing,IRCR)。算法根据认知无线电网络频谱的动态性,利用相邻节点间信道利用率,选择可靠邻节点,并根据可靠邻节点建立可靠路由。仿真结果表明,与传统频谱感知按需路由协议(spectrumaware on-demand routing protocol,SORP)相比,IRCR具有较高的数据包投递率和较低平均时延。     

认知无线电网络路由及频谱分配联合策略研究

认知无线电网络中的节点可以自主切换通信频率,从而对拓扑和路由产生影响。该文针对多跳认知无线电网络的场景提出了一种路由与频谱分配的联合策略,在按需路由的过程中完成频谱分配任务。实验结果表明,在多数据流并存的认知无线电网络中,该策略较其它路由方法具有更好的适应性和更低的累积时延。     

EERP:一种能源有效的无线传感器网络路由协议

针对同构无线传感器网络的能源瓶颈问题提出一种能源有效的自适应路由协议,该协议在分布式动态分簇的基础上提出一种班车算法对数据进行逐层汇聚,以减少网络中流动数据包的数量,同时分担簇头节点的计算量。Tossim仿真试验表明该协议能够显著地减少节点的能量开销,提高网络的适应性,有效地延长网络的生命周期。     

认知无线电网络路由及频谱分配联合策略研究

认知无线电网络中的节点可以自主切换通信频率,从而对拓扑和路由产生影响。该文针对多跳认知无线电网络的场景提出了一种路由与频谱分配的联合策略,在按需路由的过程中完成频谱分配任务。实验结果表明,在多数据流并存的认知无线电网络中,该策略较其它路由方法具有更好的适应性和更低的累积时延。     

认知无线电网络层路由问题研究

在认知无线电中,网络层用于确定如何在网络中找到一条从源节点到目标节点的路径,且数据路径应当是适应频谱状况的,即尽可能绕过主用户频繁出现的区域。由于频谱是随机的,因而数据路径也可能是随机的。文章分析认知无线电网络中路由面临的挑战,介绍认知无线电网络中的两种路由方案:静态路由和动态路由,给出静态路由频谱选择阶段的5个指标,研究静态路由下一跳选择阶段的优化问题,最后提出认知无线电网络动态路由的实现方案。     

SZM-LEACH:一种层簇式的WSN安全跨区多跳路由协议

针对经典成簇协议LEACH面临的安全威胁,提出了一种新的安全跨区多跳层簇式路由协议(SZM-LEACH).其核心思想是通过分区自治建立安全簇首表格,并在路由建立过程中通过密钥管理实现安全路径建立.仿真实验表明,改进的路由机制可以有效减少因恶意节点而导致的数据丢失,同时显著增加网络生命周期,降低网络能耗.     

认知无线电网络自适应能量驱动双门限簇头轮换算法研究

 为了延长基于分簇结构的认知无线电网络的网络寿命,需要采用簇头轮换的方法来平衡认知无线电网络的能耗.通过分析网络中簇头节点与普通节点之间的能耗差异,建立能量消耗模型,并提出了一种基于簇头节点实时负载来估计其启动簇头轮换的双门限自适应簇头轮换算法(Double Thresholds Adaptive Cluster Rotation Algorithm,DTACRA).仿真结果表明,与现有算法LEACH和EDAC算法等比较,DTACRA算法可以有效提高节点能量利用效率,延长了网络生存时间.     

认知无线网络按需协同感知和信道分配

结合路由发现和维护过程中控制消息的广播特性,提出将频谱协同感知和信道分配的交互信息部分融入路由控制消息的方法。认知用户的信息交互随按需路由发现过程而启动,并在路由沿线建立协同感知节点簇,利用路由维护消息对该节点簇进行维护。同时以认知网络容量最大化为目标,提出将频谱协同感知和信道分配联合设计。仿真分析表明,减少了认知用户的信息交互开销,缓解了认知无线网络中控制信道的瓶颈影响,对空闲频谱进行了高效再利用。     

WSN中一种基于剩余能量级别的负载均衡路由协议

文中提出了一种WSN中基于剩余能量级别的负载均衡的分簇路由协议REICRP.在簇的建立阶段,RELCRP采用了基于优先级的簇头选取策略,高优先级的节点能更早地广播簇头竞选通告,从而避免剩余能量低的节点成为簇头.簇间通信采用单跳一多跳混合传输模式,簇头节点根据剩余能量级别切换传输方式,以缓解"热点"问题.仿真结果表明:RELCRP有效地均衡了网络中节点的能量消耗,延长了网络的生存时间.     

基于簇的分布式认知无线电网络安全体系结构

针对认知无线电网络中出现的模仿主用户攻击和自私行为攻击问题,提出一种基于簇的分布式认知无线电网络安全体系结构.这种安全体系结构通过采用数据加密和认证等安全技术解决无线网络中原有的安全问题,通过在主用户基站与认知用户间使用Hash匹配技术可解决模仿主用户攻击问题,通过簇头向目的节点发送转发节点的可用频谱信息可解决自私行为攻击问题.由分析可知该安全体系结构是安全、高效和可行的.     

Diffusing-CRN k-means: an improved k-means clustering algorithm applied in cognitive radio ad hoc networks

With increasing demand of new wireless applications and increasing number of wireless user’s, problem of spectrum scarcity arises. In this context, cognitive radio supports dynamic spectrum access to address spectrum scarcity problem. Cognitive radio defined the cognitive radio nodes by their ability to intelligently adapt the environment to achieve specific objectives through advanced techniques. The variance of channel availability for cognitive radio nodes degrades connectivity and robustness of this type of network; in this case the use of clustering is an effective approach to meet this challenge. Indeed, the geographical areas are homogeneous in terms of type of radio spectrum, radio resources are better allocated by grouping cognitive radio nodes per cluster. Clustering is interesting to effectively manage the spectrum or routing in cognitive radio ad hoc networks. In this paper, we aim to improve connectivity and cooperativeness of cognitive radio nodes based on the improvement of the k-means algorithm. Our proposed algorithm is applied in cognitive radio ad hoc networks. The obtained results in terms of exchange messages and execution time show the feasibility of our algorithm to form clusters in order to improve connectivity and cooperativeness of cognitive radio nodes in the context of cognitive radio ad hoc networks.     

CR-CEA: A collision- and energy-aware routing method for cognitive radio wireless sensor networks

Currently, working in the overcrowded shared unlicensed spectrum band, leads to a reduction in the quality of communications in wireless networks. This makes a considerable increase in packet loss caused by collisions that necessitates packets retransmissions. In the case of wireless sensor networks (WSN), a large amount of energy of sensor nodes will be wasted by these retransmissions. Cognitive radio technology makes it possible for sensor nodes, to opportunistically use licensed bands with better propagation characteristics and less congestion. In this paper a routing method for cognitive radio wireless sensor networks (CR-CEA) is presented, that is based on a cross-layer design that jointly considers route and spectrum selection. The CR-CEA method has two main phases: next hop selection and channel selection. The routing is performed hop-by-hop with local information and decisions, which are more compatible with sensor networks. Primary user activity and prevention from interference with them, is considered in all spectrum decisions. It uniformly distributes frequency channels between adjacent nodes, which lead to a local reduction in collision probability. This clearly affects energy consumption in all sensor nodes. In CR-CEA, route selection is energy-aware and a learning-based technique is used to reduce the packet delay in terms of hop-count. The simulation results reveal that by applying cognitive radio technology to WSNs and selecting a proper operating channel, we can consciously decrease collision probability. This saves energy of sensor nodes and improves the network lifetime.     

A trust mechanism-based channel assignment and routing scheme in cognitive wireless mesh networks with intrusion detection

Cognitive Wireless Mesh Networks (CWMN) is a novel wireless network which combines the advantage of Cognitive Radio (CR) and wireless mesh networks. CWMN can realize seamless integration of heterogeneous wireless networks and achieve better radio resource utilization. However, it is particularly vulnerable due to its features of open medium, dynamic spectrum, dynamic topology, and multi-top routing, etc.. Being a dynamic positive security strategy, intrusion detection can provide powerful safeguard to CWMN. In this paper, we introduce trust mechanism into CWMN with intrusion detection and present a trust establishment model based on intrusion detection. Node trust degree and the trust degree of data transmission channels between nodes are defined and an algorithm of calculating trust degree is given based on distributed detection of attack to networks. A channel assignment and routing scheme is proposed, in which selects the trusted nodes and allocates data channel with high trust degree for the transmission between neighbor nodes to establish a trusted route. Simulation results indicate that the scheme can vary channel allocation and routing dynamically according to network security state so as to avoid suspect nodes and unsafe channels, and improve the packet safe delivery fraction effectively.     

Secure Distributed Routing Algorithm with Optimizing Energy Consumption for Cognitive Radio Networks

In cognitive radio networks, the non-cooperative behavior is an inherent security issue. Then it is important to guarantee the support of the cooperation among nodes. In this paper, first the distributed routing problems with optimizing energy use are translated into a 0–1 integer programming problem by analyzing the dynamical power interference among nodes. Secondly, the key allocation about end nodes is devised to realize the confidentiality about data transmission. Thirdly, a secure distributed routing algorithm (SDRA) with energy use is proposed to ensure the security on end-to-end communication. The simulation and analysis show that the energy use for the SDRA is lower than that of the spectrum and energy aware routing protocol. Moreover, the trust mechanism based on Bayesian theorem is more compatible than that of Beta function for distributed routing algorithm in the actual situation.     

认知无线电网络中基于信任的安全路由模型

针对认知无线电网络中路由受到的选择性转发攻击,提出一种基于信任的安全路由模型。通过监视节点的数据转发行为,构建节点的信任以识别恶意节点。基于路由选择必须同频谱分配紧密结合的特点,在路由发现阶段,请求信息中封装节点的可用频谱机会并避免发送给恶意节点。在路由选择阶段,利用节点信任构建可用路径信任,结合延时度量进行路由决定。同时,根据节点的信任划分对其服务请求采取不同的响应,对非可信节点的恶意行为采取更严厉的惩罚,从而激励节点在路由中的合作。仿真结果及分析表明,在选择性转发攻击下,该模型较已有模型在网络吞吐率、端到端延迟方面都有较好的表现。     

认知无线网络中基于主用户行为的联合路由和信道分配算法

针对认知无线网络中主用户行为将导致频谱瞬时变化而影响路由稳定性的问题,提出了一种基于主用户行为的路由和信道联合分配算法。该算法通过采用呼叫模型对主用户行为建模,并根据动态源路由协议的路由寻找机制,在目的节点等待多个路由请求分组后选择受主用户行为影响最小的路由,然后沿着所选定路径的反方向传送路由回复分组并完成信道分配。理论分析证明了算法中的链路平均持续时间期望与主用户活动概率成反比且具有与网络节点数成正比的计算复杂度。仿真结果表明,该算法具有比Gymkhana路由方案更高的分组投递率和更低的平均分组时延。     

认知无线Ad Hoc网络中的路由尺度和算法设计

在认知无线Ad Hoc网络中,路由问题面临巨大挑战。由于各认知节点可用频谱的时变性、多样性和差异性,传统的路由尺度不再适用于认知无线Ad Hoc网络。本文在自组织认知网络环境下,应用主用户信道的使用模型,同时考虑次用户之间的干扰情况,提出了两类路由尺度和算法,仿真结果表明,这两类路由尺度都能很好地反映端到端性能。     

认知无线电网络中抗追踪用户攻击的隐式信道选择方案(英文)

For the discontinuous occupancy of primary users in cognitive radio networks(CRN),the time-varying of spectrum holes becomes more and more highlighted.In the dynamic environment,cognitive users can access channels that are not occupied by primary users,but they have to hand off to other spectrum holes to continue communication when primary users come back,which brings new security problems.Tracking user attack(TUA) is a typical attack during spectrum handoff,which will invalidate handoff by preventing user accessing,and break down the whole network.In this paper,we propose a Channel Selection Information Hiding scheme(CSIH) to defense TUA.With the proposed scheme,we can destroy the routes to the root node of the attack tree by hiding the information of channel selection and enhance the security of cognitive radio networks.     

跳频分组无线网的路由算法分析

跳频分组无线网抗干扰性好,保密性强,广泛应用于战术通信系统。讨论了几种跳频分组无线网的路由选择算法,着重分析了针对传输多类型分组跳频网的ALR路由算法,并将此路由算法的性能与DAR算法的性能进行了比较,证实了该算法在吞吐量、端-端正确传输率等方面都优于传统的方法。