基于传输距离和Sink移动的扩延网络寿命算法

在无线传感网络WSN(Wireless Sensor Network)中,传感节点通常以多跳方式向信宿Sink传输感测数据.由于邻近信宿Sink的传感节点需要承担数据转发的任务,比其他节点消耗更多的能量,缩短了网络寿命.为此,提出一种扩延网络寿命的新算法,记为NLTA(Network LifeTime Augmentation).NLTA算法采用了节点传输距离自适应调整和信宿Sink移动两个策略.节点依据能量情况,调整传输距离,减少能量消耗,然后根据路径容量值,调整Sink的位置,平衡网内的节点能量消耗,避免信宿Sink的周围节点能量过度消耗.仿真结果表明,提出的NLTA方案能够有效地提高网络寿命.     

基于最小生成树的LEACH协议改进

LEACH(Low Energy Adaptive Clustering Hierarchy)是一种被广泛应用于无线传感网络的路由协议.本文针对LEACH协议中,远距离节点作为簇首时能量消耗过多的缺点,提出了一种改进的无线传感网络路由协议.多跳传输LEACH改进协议在节点选出簇首之后,采用最小生成树中Prim算法,在簇首与基站间采用多跳传输.为克服多跳传输时距基站第一跳的簇首能量消耗较多的缺点,阈值需要采用节点距基站的距离和节点距簇首的平均距离来调整,已达到平衡节点能量消耗的目的.仿真结果表明,改进的算法可减少和均衡能量消耗,提高能量的使用,以及延长整个网络寿命方面具有很大的优势.     

一种无线多媒体传感器网络路径最优路由算法

介绍了无线多媒体传感网络(WMSN)路由的设计原则与策略,描述了路径最优的基本原理,最后从最优路径的选择、信息转发策略、节点能量消耗3个方面考虑,设计出路径最优路由算法。该算法与蚁群算法进行比较,实验结果表明,该算法在节点能量消耗、信息传送速度上都优于蚁群算法,尤其传速率提高了30%左右。     

基于CMRA路由协议改进算法

为了延长无线传感网络的生存时间,需要设计满足高效率、低功耗的路由算法。一种CMRA（intercluster head multi-hop routing algorithm）算法被提出来,这种算法通过节点通信能量消耗模型建立最小能量路径树,但CMRA对于簇头选择的能量分配不均衡,造成簇头结点负载过重。提出一种新的路由算法CMRA-EE（CMRA-energy efficient）,在簇头选举阶段引入节点能量参数,同时将簇头节点能量与距离作为代价参数,从而平衡了网络节点能耗。通过仿真对CMRA-EE算法进行性能分析与评价,结果显示,CMRA-EE算法在延长无线传感网有效生存时间方面比CMRA算法有了明显的改善。     

一种基于LEACH的无线传感网络路由协议

针对传统无线传感网络中LEACH算法能量消耗导致节点过早死亡等问题,文中在LEACH算法的基础上提出一种改进算法。该算法首先针对普通节点和簇首节点的选取分配了不同的加权概率,在阈值上同时考虑当前节点和所有节点的总能量。该算法借助维诺图实现对簇的划分,并采用优化的A^*算法实现多跳传输技术。仿真实验结果表明,改进算法在死亡节点及能量消耗等问题上取得了较好的效果,最大循环次数之后,存活节点数量是原始算法的5倍,节点剩余能量是原始算法的8.8倍。     

新的无线传感器网络覆盖控制算法

首先,设计了节点自适应传感半径调整算法(AASR,adaptive adjustment of sensing radius),通过节点自适应选择最佳的覆盖范围,有效地进行节点覆盖控制,减少节点能量虚耗,提高覆盖效率。其次,从调整效果、能量消耗和覆盖冗余度3个方面对节点自适应传感半径调整算法进行了模拟实验和分析。仿真结果表明,AASR能够有效提高节点生存时间,减少能量消耗,提高覆盖率。     

基坑监测系统中传感网的节点部署

基坑监测系统中,需要在各监测点部署传感器节点,系统的监测点围绕基坑工程展开,其监控区域近似圆环。在基站收集监测数据时,离基站越近的区域需要转发的数据越多,节点能量消耗速度也就越快,基站附近的节点将很快消耗完能量,系统随即瘫痪。通过研究圆环形传感网的拓扑特点,得到节点密度公式,使得各区域的总能量与能量消耗速度之比达到平衡。理论分析和仿真实验表明,按照此密度公式部署传感器节点,可显著提高系统生命周期。     

基于分层的层内无线传感网络数据融合

无线传感网络数据融合能够有效减少传感节点的数据通信量,减少节点的能量消耗,延长了网络的寿命。本文提出了节点分层算法,在层内传感节点加入了具体的数据融合算法,利用拉依达准则对节点收到的数据进行异常数据检测,在上层节点利用主成分分析对剩余数据进行数据融合。通过仿真实验得出该算法数据融合结果准确率好。     

WSNs中基于智能水滴的信宿路径规划算法

为了有效避免无线传感网络(WSNs)中的热点问题,常利用移动信宿收集数据。信宿依据预定路线遍历预定的驻留点(RPs)。而其他传感节点就将数据传输至离自己最近的驻留点。因此,构建最优的RPs非常重要。为此,提出基于智能水滴的信宿路径规划(IWD-SPP)算法。提出IWD-SPP算法的目的在于延长网络寿命,并最小化转发数据包的能量消耗。利用智能水滴算法构建最优的RPs,规划信宿的移动路径。仿真结果表明,提出的IWD-SPP算法在能量消耗和网络寿命方面的性能优于同类算法。     

基于模糊聚类的传感网络失效节点检测

针对当无线传感网中的传感节点分配随机性较强,节点能量不能得到有效的补充,一旦节点能量耗尽,会造成节点失效.传统检测方法因为无法准确提取节点失效特征,造成失效节点检测的准确度不高.为了解决这一问题,提出一种基于模糊聚类失效节点搜索的检测算法,通过计算无线传感节点能量消耗的特征模糊聚类概率,运用模糊概率判定失效节点位置.实验证明,该方法能有效的对无线传感网络中失效节点进行检测,取得了不错的效果.     

Actor-oriented directional anycast routing in wireless sensor and actor networks with smart antennas

Current routing protocols in wireless sensor and actor networks (WSANs) shows a lack of unification for different traffic patterns because the communication for sensor to actor and that for actor to actor are designed separately. Such a design poses a challenge for interoperability between sensors and actors. With the presence of rich-resource actor nodes, we argue that to improve network lifetime, the problem transforms from reducing overall network energy consumption to reducing energy consumption of constrained sensor nodes. To reduce energy consumption of sensor nodes, especially in challenging environments with coverage holes/obstacles, we propose that actor nodes should share forwarding tasks with sensor nodes. To enable such a feature, efficient interoperability between sensors and actors is required, and thus a unified routing protocol for both sensors and actors is needed. This paper explores capabilities of directional transmission with smart antennas and rich-resource actors to design a novel unified actor-oriented directional anycast routing protocol (ADA) which supports arbitrary traffic in WSANs. The proposed routing protocol exploits actors as main routing anchors as much as possible because they have better energy and computing power compared to constraint sensor nodes. In addition, a directional anycast routing approach is also proposed to further reduce total delay and energy consumption of overall network. Through extensive experiments, we show that ADA outperforms state-of-the-art protocols in terms of packet delivery latency, network lifetime, and packet reliability. In addition, by offer fault tolerant features, ADA also performs well in challenging environments where coverage holes and obstacles are of concerns.     

A delay and energy aware coordination mechanism for WSAN

In this paper, a delay and energy aware coordination mechanism (DEACM) has been devised for wireless sensor–actor networks. In DEACM, a two‐level hierarchical K‐hop clustering mechanism is used to organize the sensors and actors for communication. In the first level, sensors form a K‐hop cluster using actors as cluster heads, and sink is made as the cluster head in the second level to form a cluster among actors. Sensor nodes, which are 1‐hop away from the actors, also called as relay nodes are elected as backup cluster head (BCH) based on the residual energy and node degree. BCH collects the data from sensors when an actor is away to perform actions in the affected area. The scheme is evaluated through exhaustive simulation in NS2 along with other existing schemes. Different parameters like average event waiting time, event reliability, and average energy dissipation are compared, varying the number of sensors, actors, and data transfer rate. In general, it is observed that the proposed DEACM outperforms other existing schemes. Copyright © 2016 John Wiley & Sons, Ltd.     

A Real-Time and Reliable Transport (RT)$^{2}$ Protocol for Wireless Sensor and Actor Networks

Wireless sensor and actor networks (WSANs) are characterized by the collective effort of heterogeneous nodes called sensors and actors. Sensor nodes collect information about the physical world, while actor nodes take action decisions and perform appropriate actions upon the environment. The collaborative operation of sensors and actors brings significant advantages over traditional sensing, including improved accuracy, larger coverage area and timely actions upon the sensed phenomena. However, to realize these potential gains, there is a need for an efficient transport layer protocol that can address the unique communication challenges introduced by the coexistence of sensors and actors. In this paper, a real-time and reliable transport (RT) protocol is presented for WSANs. The objective of the (RT) protocol is to reliably and collaboratively transport event features from the sensor field to the actor nodes with minimum energy dissipation and to timely react to sensor information with a right action. In this respect, the (RT) protocol simultaneously addresses congestion control and timely event transport reliability objectives in WSANs. To the best of our knowledge, this is the first research effort focusing on real-time and reliable transport protocol for WSANs. Performance evaluations via simulation experiments show that the (RT) protocol achieves high performance in terms of reliable event detection, communication latency and energy consumption in WSANs.     

事件驱动的带执行器无线传感器网络分簇算法研究

带有执行器的无线传感器网络是指在传统无线传感器网络中加入执行节点,形成传感器节点、执行节点和基站共同构成的三层监控网络。根据执行器在能量、计算能力和感知能力方面的优势,提出建立应用于事件调度的双环分簇算法。算法将执行器连接成双环结构,提升网络在线扩展能力的同时,也为无线传感器网络满足事件驱动构建基础。仿真实验证明,此算法能够有效降低网络能耗,随着节点数目的增加和监控领域的扩大,表现更加凸出。     

A PMC-driven methodology for energy estimation in RVC-CAL video codec specifications

In this paper, an energy estimation methodology based on performance monitor counters (PMC) is proposed to estimate the energy consumption of RVC-CAL video codec specifications. The proposed PMC-driven methodology is able to automatically identify the most appropriate events and training data to cover the main application characteristics. In addition, knowledge of the hardware platform employed is not required. Therefore, this methodology can be easily implemented on other PMC-available systems while keeping the estimation accuracy. It is worth noting that this is an attractive asset to analyze the energy consumption of RVC-CAL codec specifications. Besides, the methodology reduces the PMC redundancy and, thus, the overhead introduced when applied to on-line power management. Experimenting on two RVC-CAL decoders, H.264 and MPEG4 Part2 SP, a coarse estimation model based on instructions per cycle (IPC) and the proposed PMC-driven model are compared. The results show that the PMC-driven model can achieve for the H.264 and MPEG4 Part2 SP decoders average estimation errors of 5.95% and 5.01%, respectively, in comparison to the 17.11% and 13.65% average errors obtained with the IPC-based model. As a consequence, this methodology is suggested to be combined into the RVC framework to help the designer to have an overview of the energy consumption of the specification actors at earlier design stages.     

Magnetic induction based cluster optimization in non-conventional WSNs: A cross layer approach

Conventional Radio Frequency (RF) communication technique is unsuitable for communication in non-conventional media (water, soil, rocks, etc.) because of heavy losses incurred due to dynamic channel characteristics. Magnetic Induction (MI) communication overcomes these losses as it is least affected by such varying channel characteristics. In non-conventional media based Wireless Sensor Networks (WSNs) the deployed sensor nodes cannot replace or replenish their batteries. Thus, energy consumption should be minimized and that can be achieved by clustering process. This process involves data sensing, aggregation and routing to the base station. These sub-tasks are performed under Physical (PHY), Medium Access Control (MAC) and Network (NET) layers of OSI Network model. Having lesser or larger number of clusters has different impact on energy consumption in different layers’ perspective. A large number of clusters decreases energy consumption as per PHY layer whereas it results in increased energy consumption as per MAC and NET layers. Thus, a trade-off is required to minimize the overall energy consumption. To this end, we found an optimal number of clusters considering the simultaneous influence of all three layers. The above analysis is performed for three media viz. sea water, fresh water and dry soil.     

Communication and Coordination in Wireless Sensor and Actor Networks

In this paper, coordination and communication problems in wireless sensor and actor networks (WSANs) are jointly addressed in a unifying framework. A sensor-actor coordination model is proposed based on an event-driven partitioning paradigm. Sensors are partitioned into different sets, and each set is constituted by a data-delivery tree associated with a different actor. The optimal solution for the partitioning strategy is determined by mathematical programming, and a distributed solution is proposed. In addition, a new model for the actor-actor coordination problem is introduced. The actor coordination is formulated as a task assignment optimization problem for a class of coordination problems in which the area to be acted upon needs to be optimally split among different actors. An auction-based distributed solution of the problem is also presented. Performance evaluation shows how global network objectives, such as compliance with real-time constraints and minimum energy consumption, can be achieved in the proposed framework with simple interactions between sensors and actors that are suitable for large-scale networks of energy-constrained devices.     

一种自路由群组交换结构的无缓存能耗优化模型

考虑到缓存是路由交换通信设备能耗的主要来源,该文从交换网络无缓存节能的构想出发,提出了一种自路由群组交换结构的无缓存能耗优化模型。该模型采用G倍统计线复用路由单元和Banyan类交换互连建立群组交换结构,在满足业务对阻塞率和时延性能要求的基础上,采用无内部缓存、路由单元输入输出端口数扩展和级间互连线优化设计来达到节能的目的。相同网络性能下,缓存能耗和结构能耗的量化比较表明该无缓存结构能耗小。仿真实验结果证明:结构参数G越大,网络级数k越小,路由单元能耗越小,在Banyan类交换互连结构中,分治(Divide-and-Conquer, DC)互连方式的级连线能耗最小。     

基于局域信息和能量因素的WSN关键点判定算法

In the existing key node decision methods for wireless sensor network,the judgment index was so single that the result judged was deficient.In order to solve this problem,a new key node decision algorithm(KNDA)based on local information and energy factor was proposed.Firstly,the local information model based on the degree and neighbor information of node was established.Secondly,according to the residual energy of node and the change of network energy consumption after the node failed,the models of energy factors were established.Finally,an aggregative key node decision model was formed.Extensive simulation experiments were carried out in the MATLAB simulation platform,by comparing with other algorithms,the results verify that the key nodes obtained by this algorithm are more sufficient.Meanwhile when the key nodes judged by KNDA are protected,the network can show strong invulnerability.     

A Distributed Multi-competitive Clustering Approach for Wireless Sensor Networks

Wireless sensor networks (WSNs) need simple and effective approaches to reduce energy consumption because of limited energy. Clustering nodes is an effective approach to make WSNs energy-efficient. In this paper we propose a distributed multi-competitive clustering approach (DMCC) for WSNs. First, the nodes with high residual energy are selected to act as cluster head candidates (CHCs). Second, cluster heads (CHs) are selected from the CHCs based on a hybrid of competition. If the distances to the selected CHs are suitable, a CHC with more neighbor nodes and smaller average distance to its neighbor nodes is more likely to become a CH. If the number of CHs selected from the CHCs is insufficient, more CHs are selected from non-CHCs continually according to residual energy until the CHs number is suitable. DMCC makes the CHs number stable and distribute the CHs evenly. Simulation experiments were performed on to compare DMCC with some related clustering approaches. The experimental results suggest that DMCC balances the load among different clusters and reduces the energy consumption, which improves the network lifetime.