负载均衡的无线传感器网络拓扑控制算法

针对无线传感器网络节点能耗分布不均匀的问题,提出一种负载均衡的拓扑控制算法,该算法将节点看作数据转发节点,把节点间距离和节点剩余能量作为拓扑构建的依据,对剩余能量较少的节点赋予一定的节点度约束,从而均衡网络负载,解决网络中部分节点因负载过重而导致的能耗过大问题,有效延长网络生命期。     

基于概率触发的负载均衡区域竞选分簇算法

无线传感器网络中由最大连通度生成簇算法得到的簇结构,各簇头节点间负载不均衡,能量消耗较快。对止,用剩余能量和发射功率构建综合权值来决定节点竞选簇头的可能性,并通过设计的拓扑维护概率适当性的对网络拓扑进行局部调整,形成了基于概率触发的负载均衡区域竞选分簇算法,有效地延长了网络生命期。     

基于概率触发的负载均衡区域竞选分簇算法

无线传感器网络中由最大连通度生成簇算法得到的簇结构,各簇头节点间负载不均衡,能量消耗较快。对止,用剩余能量和发射功率构建综合权值来决定节点竞选簇头的可能性,并通过设计的拓扑维护概率适当性的对网络拓扑进行局部调整,形成了基于概率触发的负载均衡区域竞选分簇算法,有效地延长了网络生命期。     

无线传感器网络中一种基于标记的能量平衡路由

为实现数据的高效传输和网络生命期的最大化,提出了一种基于标记的能量平衡（LBEB）路由。该路由先向网络中嵌入多棵独立最短路径树,以构建一个虚拟树型标记系统,然后基于此标记系统设计针对不同数据类型的转发策略：紧急数据使用贪婪策略转发以保障其时延要求;而平常数据则综合考虑邻居节点的负载和剩余能量情况使用平衡策略转发以缓解拥塞并均衡节点能耗。2种策略相辅相成,共同完成预期目标。仿真结果表明：LBEB能以适量开销获得较好的路由性能,并且能在满足数据时延要求的同时均衡网络能耗从而使网络生命期最大化。     

WSN中基于非均匀簇的混合多跳路由协议*

为节省数据传输过程中消耗的能量,均衡网络节点间的能耗,提出一种基于非均匀簇的混合多跳路由协议。在无线传感器网络数据传输阶段,源簇头节点通过转发权值函数选择数据转发的中继节点,转发权值由用于降低链路通信代价的距离因子和减少剩余能量较少的簇头节点成为中继节点的概率惩罚因子共同决定,达到均衡网络能耗的目的。通过NS2仿真实验验证了算法的有效性,能够很好地均衡节点负载和提高能量利用率。     

Square Grid结构无线传感网数据传输的源路由策略分析

无线传感网中的汇聚传输模式使得靠近汇聚点的节点承担了较多的数据转发业务,导致这些节点能量很快耗尽,造成网络节点负载分布不均衡。针对这种汇聚传输问题,结合规则拓扑结构的对称性和预知性,提出基于Square Grid规则拓扑结构中分析典型源路由策略,设计一种计算路由节点负载分布的转发指数,并依据该转发指数分析各路由策略负载性能的方法。通过Mathematica绘制各路由节点负载分布图并对比各路由策略的转发指数,实验结果验证了Balancing Forwarding路由策略的节点具有较均衡的负载分布。该方法能有效地应用于评价路由策略的优劣。     

无线传感器网络最大生命期聚合树路由算法

提出了一种无线传感器网络最大生命期聚合树路由算法,根据能量等限制条件建立线性规划模型。考虑到网络最大生命期是NP难问题,在算法复杂度较低情况下,将网络最大生命期问题转化为网络最小归一化负载问题,在建立最大归一化负载聚合树过程中,不断调整负载较重节点的数据转发压力,最终建立一棵负载较轻的数据融合树,实现了网络生命期的最大化。通过仿真验证了算法的性能,并表明所提出算法可以有效延长网络生命期。     

基于社区的机会网络中能量有效消息传输

针对机会网络中消息转发的特点,综合考虑节点移动的社区特性和能量有效传输策略,提出基于社区的能量有效消息转发算法（EEMF）,将节点的剩余能量与节点间的相遇概率作为消息是否转发的关键因素,并在社区内和社区间采取不同的消息转发策略,在提高消息传输成功率的同时,降低网络负载,减少节点能耗,延长网络的生命期。仿真实验结果表明,该算法与PRoPHET, MaxProp, CMTS, CMOT等经典算法相比,达到了预期的效果。     

基于路径损耗的WSN能量意识拓扑控制算法

为延长无线传感器网络(WSN)中节点的生命周期及均衡节点负载,在PLBD算法的基础上提出一种基于路径损耗的能量意识拓扑控制算法PLEATC。该算法使用损耗链路作为度量标准,同时考虑转发节点的剩余能量状况,避免网络中部分节点因负载过重而导致能量提前耗尽。仿真结果表明,用PLEATC算法构建的拓扑能够保证网络的连通性和健壮性,并延长网络寿命。     

方格拓扑无线传感器网络源路由策略的能耗分析

无线传感器网络(WSNs)中的汇聚传输模式使得靠近汇点的节点承担了较多的数据转发业务,导致这些节点能量很快耗尽,降低网络的寿命。针对这种问题,结合规则拓扑结构的对称性和预知性,对方格拓扑结构中多种典型源路由策略进行分析,分别计算各策略的瓶颈节点负载和数据传输时延,提出能耗的计算模型,并据此探讨网络节点的通信能耗、待机能耗和总能耗。数值分析结果表明:均衡转发策略产生最小的总能耗。     

IRPL: An energy efficient routing protocol for wireless sensor networks

This study aims to overcome the disadvantages of the original RPL (IPv6 Routing Protocol for Low power and Lossy networks) routing protocol (RPL including problems with energy consumption and energy load balance). We developed a relatively balanced RPL – the improved protocol (IRPL). This protocol is based on an efficient clustering algorithm and an effective topology control model of the loop domain communication route. The clustering algorithm can be used to calculate the optimal number of cluster heads by assumption of the network model. Combined with the clustering probability model and the node competition mechanism, the cluster head node in the wireless sensor network was used to complete the clustering process. In the topology control model, the wireless sensor network was divided into concentric rings with equal areas. Nodes determined the best network route, depending on different levels of ring domain and the optimal forwarding communication area defined in this study. Simulation results indicate that the IRPL routing protocol can reduce overall network energy consumption, balance network energy consumption, and prolong network lifetime.     

Termite-hill: Performance optimized swarm intelligence based routing algorithm for wireless sensor networks

A wireless sensor network (WSN) is a large collection of sensor nodes with limited power supply, constrained memory capacity, processing capability, and available bandwidth. The main problem in event gathering in wireless sensor networks is the formation of energy-holes or hot spots near the sink. Due to the restricted communication range and high network density, events forwarding in sensor networks is very challenging, and require multi-hop data forwarding. Improving network lifetime and network reliability are the main factors to consider in the research associated with WSN. In static wireless sensor networks, sensors nodes close to the sink node run out of energy much faster than nodes in other parts of the monitored area. The nodes near the sink are more likely to use up their energy because they have to forward all the traffic generated by the nodes farther away to the sink. The uneven energy consumption results in network partitioning and limit the network lifetime. To this end, we propose an on-demand and multipath routing algorithm that utilizes the behavior of real termites on hill building termed Termite-hill which support sink mobility. The main objective of our proposed algorithm is to efficiently relay all the traffic destined for the sink, and also balance the network energy. The performance of our proposed algorithm was tested on static, dynamic and mobile sink scenarios with varying speed, and compared with other state-of-the-art routing algorithms in WSN. The results of our extensive experiments on Routing Modeling Application Simulation Environment (RMASE) demonstrated that our proposed routing algorithm was able to balance the network traffic load, and prolong the network lifetime.     

Optimal energy allocation in heterogeneous wireless sensor networks for lifetime maximization

We consider the problem of optimal energy allocation and lifetime maximization in heterogeneous wireless sensor networks. We construct a probabilistic model for heterogeneous wireless sensor networks where sensors can have different sensing range, different transmission range, different energy consumption for data sensing, and different energy consumption for data transmission, and the stream of data sensed and transmitted from a sensor and the stream of data relayed by a sensor to a base station are all treated as Poisson streams. We derive the probability distribution and the expectation of the number of data transmissions during the lifetime of each sensor and the probability distribution and the expectation of the lifetime of each sensor. In all these analysis, energy consumption of data sensing and data transmission and data relay are all taken into consideration. We develop an algorithm to find an optimal initial energy allocation to the sensors such that the network lifetime in the sense of the identical expected sensor lifetime is maximized. We show how to deal with a large amount of energy budget that may cause excessive computational time by developing accurate closed form approximate expressions of sensor lifetime and network lifetime and optimal initial energy allocation. We derive the expected number of working sensors at any time. Based on such results, we can find the latest time such that the expected number of sensors that are still functioning up to that time is above certain threshold.     

无线传感器网络非均匀等级分簇拓扑结构研究

网络拓扑结构影响着传感器节点的负载均衡与生存周期,分簇结构是无线传感网络的一种有效地拓扑管理方式。根据血管网络特征以及对构建无线传感器网络拓扑结构的启示,提出了无线传感器网络非均匀等级分簇拓扑结构。分析血管网络结构特征,建立数学模型和网络拓扑结构,对具有压力差的网络节点进行等级标定。根据改进粒子群算法进行非等概率静态分簇,形成不同等级区域具有密度和规模不等的非均匀等级分簇拓扑结构。仿真分析表明,此算法能优化网络分簇,均衡节点能耗,延长网络生命期,避免网络能耗热点问题。     

无线传感器网络中负载均衡的sink节点移动策略

在无线传感器网络中,部分传感器节点由于担任过多数据中转任务,需要消耗较多的能量.使其过早死亡.缩短了网络的寿命.本文提出基于sink节点移动的策略.将感知区域分割成有限个虚拟单元格,并以每个虚拟单元格的中心作为sink节点的备选移动位置.然后,通过解线性规划问题确定sink节点的移动位置和停留时间.通过此方法.在一定程度上均衡了传感器节点的负载.延长了网络寿命.     

Forwarding via checkpoints: Geographic routing on always-on sensors

Data forwarding is an essential function in wireless sensor networks (WSNs). It is well-known that geographic forwarding is an efficient scheme for WSNs as it requires maintaining only local topology information to forward data to a central gathering point, called the sink (or base station), for further analysis and processing. In this paper, we propose an energy-efficient data forwarding protocol for WSNs, called Weighted Localized Delaunay Triangulation-based data forwarding (WLDT), with a goal to extending the network lifetime. Specifically, WLDT selects as forwarders the sensors with high remaining energy and whose locations lie nearer the shortest path between source sensors and a single sink, thus helping the sensors minimize their average energy consumption. More precisely, WLDT defines checkpoints to build energy-efficient data forwarding paths and uses a 1-lookahead scheme to guarantee data delivery to the sink. We show that WLDT, which favors data forwarding through short Delaunay edges, achieves an energy gain percentage in the order of 55% for the free space model and close to 100% for the multi-path model compared to BVGF and GPSR, which forward data through long distances and which we have slightly updated to account for energy in the selection of next forwarders. We prove that these checkpoints yield an energy gain percentage in the order of 30% in comparison with a similar protocol, called WLDT-w/c (or WLDT without checkpoints), which forwards data via short distances but does not use checkpoints.     

一种基于非均匀分簇的无线传感器网络路由协议

在路由协议中利用分簇技术可以提高无线传感器网络的可扩展性.当簇首以多跳通信的方式将数据传输至数据汇聚点时,靠近汇聚点的簇首由于转发大量数据而负载过重,可能过早耗尽能量而失效,这将导致网络分割.该文提出一种新颖的基于非均匀分簇的无线传感器网络多跳路由协议.它的核心是一个用于组织网络拓扑的能量高效的非均匀分簇算法,其中候选簇首通过使用非均匀的竞争范围来构造大小不等的簇.靠近汇聚点的簇的规模小于远离汇聚点的簇,因此靠近汇聚点的簇首可以为簇间的数据转发预留能量.模拟实验结果表明,该路由协议有效地平衡了簇首的能量消耗,并显著地延长了网络的存活时间.     

基于蚁群的无线传感网最大化生存时间路由

为提高无线传感网的生存时间,对基于蚁群算法的最大化生存时间路由(MLRAC)进行了研究。该路由利用链路能耗模型和节点发送数据概率,计算一个数据收集周期内节点总能耗。同时考虑节点初始能量,建立了最大化生存时间路由的最优模型。为求解该最优模型,在经典蚁群算法的基础上,提出修正的蚁群算法。该算法采用新的邻居节点转发概率公式、信息素更新公式和分组探测方法,经过一定的迭代计算获得网络生存时间的最优值和每个节点的最优发送数据概率。最后,Sink节点洪泛通知网络中所有节点。节点根据接收到的最优概率,选择数据分组未经过的邻居节点发送数据。仿真实验表明,经过一定时间的迭代,MLRAC的生存时间可以收敛到最优值。该算法能延长网络生存时间,在一定的条件下,MLRAC算法比PEDAP、LET、Ratio-w、Sum-w等算法更优。     

能量感知的GPSR动态路由负载均衡

贪婪周边无状态路由协议（GPSR）在Ad Hoc和传感器网络中有广泛的应用,GPSR的路由是以距离目的坐标最近的原则进行选路的,容易形成热点路由,从而缩短网络的生存时间。基于对邻居传感器节点的能量感知,提出了有动态负载均衡能力的GPSR路由算法。该算法能够根据网络节点的能量情况动态调整路由。仿真结果表明提出的具有动态路由负载均衡能力的GPSR算法能有效延长网络的生存时间。