基于满Steiner树问题的水下无线传感器网络拓扑愈合算法研究

建立了水下无线传感器网络模型,对拓扑愈合问题进行了形式化描述,该问题最终映射到数学上的满Steiner树问题.针对满Steiner树问题设计了一种近似的拓扑愈合算法,通过把自移动节点迁移至合适位置,不仅使拓扑得以愈合,还能够改善时延和能耗指标.仿真实验结果表明,该算法能愈合通信拓扑至较优状态,降低了传输时延和能耗,并能有效地延长水下传感器网络生命期.     

高效能耗传感器网络的模型分析与路由算法设计

传统的传感器网络生命期模型未考虑节点异跳上单位传输费用的差异性,针对该缺点本文建立生命期模型并转化目标为带不等式约束的最大费用最大流问题,依据模型中所体现路由规划与生命期优化的本质联系,提出一种基于节点负载压力的自适应路由算法,算法实现所需的计算量、通信量较小.通过仿真实验对算法进行了性能分析和验证,仿真结果表明该算法能有效地延长传感器网络生命期.     

基于二跳信息的分簇算法

对于低功耗自组织的无线传感器网络,其路由协议和拓扑控制受到了很多学者的关注,且已成为国际的研究热点.在分析了LEACH,FSR算法的基础上,提出了一种基于二跳信息的分簇算法,以有效提高网络生命期.着重对算法的设计思想和工作过程,包括簇首选择与簇建立,簇成员通信等进行了分析和论述.仿真结果表明本文中的算法对于LEALCH能有效提高网络生命期.     

无线传感器网络中能量感知目标定位算法

在传感器网络中节点能量有限,因此设计出能量高效的目标定位算法对于延长网络生命期、增强网络健壮性有着非常重要的意义.提出了一种能量高效的目标定位算法,并提出了在节点稀疏情况下保证定位精确性的方法.仿真表明,使用文中提出算法的传感器网络能大大地降低能量损耗.     

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。     

多基站数据聚合无线传感器网络中的最大生命期路由

研究了多基站数据聚合无线传感器网络中的最大生命期路由问题.首先证明该类问题具有NP-hard性质,然后提出一种基于最小生成森林的启发式算法,并采用次梯度方法设计了分布式算法,最后通过大量的仿真实验分析所提路由算法性能,并给出分布式算法的收敛性能.     

LEACH算法在无线传感器网络中的应用改进

基于WSN网络的节点生存能力强、部署方便、网络规模大、节点网络自组织和网络智能化等技术特点和优势,使得无线传感器网络应用于自然灾害预警成为可能。本文基于WNS技术基础提出了一种山体滑坡监控系统,重点讨论了拓扑控制技术,针对网路拓扑LEACH算法中所存在的问题提出了改进方案,LEACH算法的改进不仅降低了WSN网络的电路能耗,也降低了网络自组织时产生的路由消耗,增强了网络的健壮性。     

基于电量均衡的无线传感器网络分簇算法

为了延长无线传感器网络的生命期,针对节点能耗分布不均匀的问题,提出一种电量均衡的分簇算法.该算法将节点剩余能量作为构建分簇结构的依据,对剩余能量较少的节点赋予一定的约束,使之成为普通节点,并使电量多的节点成为簇头节点,均衡网络电量负载,解决了网络中部分低电量节点担任骨干节点而导致能耗的问题,从而有效延长了网络的生命期.仿真实验证明了该算法的有效性.     

基于最优刚性图的能量有效分布式拓扑控制算法

针对现有无线传感器网络拓扑控制算法无法平衡各节点能量消耗的问题,基于最优刚性图提出了一种具有平衡负载特性的能量有效分布式拓扑控制算法。算法引入综合反映能量消耗及剩余能量两方面因素的链路权值函数,能够根据当前节点剩余能量实时地动态优化拓扑结构,从而有效地平衡网络节点的能量消耗。从理论上证明了优化后的拓扑是2?连通的而且具有稀疏性;同时优化后拓扑中各节点的平均度趋于4。仿真结果表明,与其他算法相比,该算法能够有效地平衡各节点的能量消耗,进而延长网络生命期。     

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.     

基于模拟退火算法的风电场消纳线路负载拓扑结构研究

基于当前线路负载率具有较高的突发性、较高的实时性等特点,将对线路资源利用率和电流控制问题所采用的模拟退火算法进行风电场拓扑结构模型优化。利用模拟退火算法对线路负载均衡问题进行搜索,随后在全局最优区域附近进行局部拓扑结构优化,就可以找到线路负载均衡问题最优解。仿真研究表明,此方法不但完善了局部搜索速度,还提高了线路消纳的利用率,明显改善了线路拓扑负载不均衡的情形,进而可以为大型风电场建设中的功率设备线路拓扑优化提供有效的参考。     

局部构造邻居最优能耗路的拓扑控制算法

无线传感器网络拓扑控制算法的首要任务是减少节点的能量消耗,从而延长整个网络的生存时间。而传感器节点大部分的能量消耗在无线通信模块。在分析了拓扑控制算法所基于的两种模型(UDG,MG)以及两种不同性质的网络(homogenous net,heterogeneous net)的基础上,考虑到在通常情况下,无线通信的能量消耗与通信距离的3次方成正比。基于此,针对能否设计一种选择邻居的标准,使邻居间的链接都是最小能耗链接这一问题,给出了一种构造最小能耗路的邻近图算法MEP(MG)。证明了算法具有连通性和1-spanner特性。     

An energy‐efficient localized topology control algorithm for wireless ad hoc and sensor networks

Topology control plays an important role in the design of wireless ad hoc and sensor networks and has demonstrated its high capability in constructing networks with desirable characteristics such as sparser connectivity, lower transmission power, and smaller node degree. However, the enforcement of a topology control algorithm in a network may degrade the energy‐draining balancing capability of the network and thus reduce the network operational lifetime. For this reason, it is important to take into account energy efficiency in the design of a topology control algorithm in order to achieve prolonged network lifetime. In this paper, we propose a localized energy‐efficient topology control algorithm for wireless ad hoc and sensor networks with power control capability in network nodes. To achieve prolonged network lifetime, we introduce a concept called energy criticality avoidance and propose an energy criticality avoidance strategy in topology control and energy‐efficient routing. Through theoretical analysis and simulation results, we prove that the proposed topology control algorithm can maintain the global network connectivity with low complexity and can significantly prolong the lifetime of a multi‐hop wireless network as compared with existing topology control algorithms with little additional protocol overhead. Copyright © 2008 John Wiley & Sons, Ltd.     

Simulated annealing-based algorithms for the studies of thethermoelastic scaling behavior

Simulated annealing is a robust and easy-to-implement algorithm for material simulation. However, it consumes a huge amount of computational time, especially on the studies of percolation networks. To reduce the running time, we parallelize the simulated annealing algorithm in our studies of the thermoelastic scaling behavior of percolation networks. The critical properties of the thermoelastic moduli of percolation networks near the threshold p_c are investigated by constructing a square percolation network. The properties are tested by simulations of a series of two-dimensional (2-D) percolation networks near p_c. The simulations are performed using a novel parallelizing scheme on the simulated annealing algorithm. To further accelerate the computational speed, we also propose a new conjectural method to generate better initial configurations, which speeds up the simulation significantly. Preliminary simulation results show surprisingly that the percolating phenomenon of thermal expansion does exist under certain conditions. The behavior seems to be governed by the elastic properties of a percolation network     

Distributed Topology Construction in ZigBee Wireless Networks

Topology control is one of the important techniques in wireless multi-hop networks to preserve connectivity and extend the network lifetime. This is more significant in ZigBee, since the address assignment scheme is tightly coupled with topology construction. For example, there can be orphan nodes that cannot receive the network address and isolated from the network due to predefined network configurations. In this paper, we propose a distributed topology construction algorithm that controls the association time of each node in order to solve the orphan node problem in ZigBee as well as construct an efficient routing tree topology. The main idea of the distributed topology construction algorithm is to construct primary backbone nodes by propagating the invitation packets and controlling the association time based on the link quality. Since the dynamically selected primary nodes are spread throughout the network, they can provide backbone to accept the association requests from the remaining secondary nodes which are majority in a network. In the performance evaluation, we show that the proposed topology construction algorithm effectively solves the orphan node problem regardless of network density as well as provides efficient tree routing cost comparable to the approximation algorithm for degree constrained minimum routing cost tree (DC-MRCT) problem.     

面向高动态移动自组织网络的生物启发分簇算法

分簇可以有效地提高大规模移动自组织网络的性能.但高动态的移动自组织网络具有节点移动性强、网络拓扑变化快的特点,应用传统的分簇算法会造成网络性能迅速下降,频繁的簇拓扑更新造成了簇结构的不稳定和控制开销的增加.为了解决传统分簇算法无法适应高动态的大规模移动自组织网络的问题,提出了一种基于生物启发的移动感知分簇算法,该算法对多头绒泡菌的觅食模型进行了改进,使其适用于移动自组织网络领域.由于该算法与节点的移动特性进行了结合,所以该算法可以有效地在高动态移动自组织网络中进行簇的建立与维护.实验结果表明,相较于其他传统分簇算法,本文算法提高了平均链路连接保持时间和平均簇首保持时间,使得簇结构更加稳定,提高了对高动态、大规模移动自组织网络的适应能力.     

Simulated Annealing Based Multi-constrained QoS Routing in Mobile ad hoc Networks

Multi-constrained quality-of-service routing (QoSR) is to find a feasible path that satisfies multiple constraints simultaneously, which is a big challenge for mobile ad hoc networks (MANETs) where the topology may change constantly. It has been proved that such a problem is NP-complete. Heuristic algorithms with polynomial and pseudo-polynomial-time complexities are often used to deal with this problem. However, existing solutions, most of which suffered either from excessive computational complexities or from low performance were proposed only for wired networks and cannot be used directly in wireless MANETs. In this paper a novel QoS routing algorithm based on Simulated Annealing (SA_RA) is proposed. This algorithm first uses an energy function to translate multiple QoS weights into a single mixed metric and then seeks to find a feasible path by simulated annealing. The paper outlines simulated annealing algorithm and analyzes the problems met when we apply it to QoSR in MANETs. Theoretical analysis and experiment results demonstrate that the proposed method is an effective approximation algorithms showing better performance than the other pertinent algorithm in seeking the (approximate) optimal configuration within a period of polynomial time.     

A Novel and Secure Secret Sharing Algorithm Applied to Insecure Networks

Being independent of any fixed equipment, Ad Hoc wireless sensor networks, a kind of acentric and self-organized wireless network, possesses some features such as easiness of deployment, strong invulnerability and flexibility of networking, which leads to a promising application prospect in terms of UAV military and civilian use. This paper proposes a new slot adaptive 4D network clustering algorithm based on UAV autonomous formation and reconfiguration to solve the problem of UAV Ad Hoc network such as networking confusion, poor network reconstruction performance, huge energy consumption and other issues. The algorithm can optimize the topology of UAVs network. We build the network topology and generate clustering network by the slot adaptive 4D network clustering algorithm in Matlab. According to the real combat of UAV, four states are simulated and analyzed. The simulation results validate the feasibility of the slot adaptive 4D network clustering algorithm. The clustering structure generated by the slot adaptive 4D network clustering algorithm is robust and the algorithm is suitable for the UAV group operation.

     

Maximum lifetime broadcast communications in cooperative multihop wireless ad hoc networks: Centralized and distributed approaches

We investigate the problem of broadcast routing in energy constrained stationary wireless ad hoc networks with an aim to maximizing the network lifetime measured as the number of successive broadcast sessions that can be supported. We propose an energy-aware spanning tree construction scheme supporting a broadcast request, considering three different signal transmission schemes in the physical layer: (a) point-to-point, (b) point-to-multipoint, and (c) multipoint-to-point. First we present a centralized algorithm that requires global topology information. Next, we extend this to design an approximate distributed algorithm, assuming the availability of k-hop neighborhood information at each node, with k as a parameter. We prove that the centralized scheme has time complexity polynomial in the number of nodes and the distributed scheme has a message complexity that is linear in the number of nodes. Results of numerical experiments demonstrate significant improvement in network lifetime following our centralized scheme compared to existing prominent non-cooperative broadcasting schemes proposed to solve the same lifetime maximization problem in wireless ad hoc networks. Due to lack of global topology information, the distributed solution does not produce as much advantage as the centralized solution. However, we demonstrate that with increasing value of k, the performance of the distributed scheme also improves significantly.     

MST-based topology control with NLOS location error compensation for location-aware networks

The topology control algorithms can improve the network capacity and network lifetime in location-aware networks. The topology control algorithms require accurate locations of mobile nodes or distances between each of the mobile nodes. The IEEE 802.15.4a-based location-aware networks can provide precise ranging distance between two mobile nodes. The mobile nodes can obtain their accurate locations by using accurate ranging distances. However, in the IEEE 802.15.4a networks, the ranging distance has a large measurement error in non-line-of-sight (NLOS) conditions. In this paper, we propose MST-based topology control with NLOS location error compensation algorithm to improve location accuracy and prevent mobile nodes from connecting to unstable links in NLOS condition. Performance evaluation shows the proposed algorithm constructs a topology map which has low location errors with considering the instability of NLOS links in NLOS condition.