Balancing the power consumption speed in flat and hierarchical WSN

A combination of a cluster tree routing protocol and an Ad hoc on demand vector (AODV) routing protocol is used in the latest ZigBee standard wireless sensor networks (WSNs) technology. However, the AODV routing protocol has no means by which to take into consideration the power consumption of the nodes during the routing process. Therefore, a new approach is proposed in this paper to balance the power consumption speed and to distribute the responsibilities of routing among fiat wireless sensor nodes and the three levels of hierarchical wireless sensor nodes. These three levels are based on the three types of devices, which are used in the ZigBee standard: the coordinator, the touters, and the end devices. In this paper, we have compared the original AODV routing protocol with our extension approach for the distribution of power consumption. Based on the simulation results, our new approach has achieved better performance in terms of increasing the lifetime of the fiat wireless sensor network, the personal area network (PAN)coordinator, the touters, and the whole network of the hierarchical wireless sensor network. Additionally, it has better performance in terms of distributing the power consumption among the key nodes of the wireless sensor network.     

A cross-layer fault tolerance management module for wireless sensor networks

It is a well-established fact that wireless sensor networks (WSNs) are very power constraint networks, but besides this, they are inherently more fault-prone than any other type of wireless network and their protocol design is very application specific. Major reasons for the faults are the unpredictable wireless communication channel, battery depletion, as well as fragility and mobility of the nodes. Furthermore, as traditional protocol design methods have proved inadequate, the cross-layer design (CLD) approach, which allows for interactions between different layers, providing more flexible and energy-efficient functionality, has emerged as a viable solution for WSNs. In this study we define a fault tolerance management module suitable to the requirements, limitations, and specifics of WSNs, encompassing methods for fault detection, fault prevention, fault management, and recovery. The suggested solution is in line with the CLD approach, which is an important factor in increasing the network performance. Through simulations the functionality of the network is evaluated, based on packet loss, delay, and energy consumption, and is compared with a similar solution not including fault management. The results achieved support the idea that the introduction of a unified approach to fault management improves the network performance as a whole.     

Energy saving in wireless sensor networks

With the development of low-cost processor, memory, and radio technologies, it becomes possible to build inexpensive wireless micro-sensor nodes. However, energy is the biggest constraint to wireless sensor capabilities and such constraint combined with a typical deployment of large numbers of sensor nodes have posed many challenges to the design and management of sensor networks. Due to their ad-hoc deployment in hazardous environment, once sensor nodes are deployed in a sensor network, they cannot be easily replaced or recharged. Thus, energy saving acts as one of the hottest topics in wireless sensor networks （WSNs） and hence several energy conservation schemes have been proposed in the literature. In this work, we will make a short survey on the main techniques used for energy conservation in sensor networks. Specifically, we will focus primarily on duty cycling schemes which represent the most suitable technique for energy saving. Moreover, we will also survey in-network processing and network coding techniques which can guarantee a significant amount of energy saving in packet transmission. Finally, we will make a review on some communication protocols proposed for sensor networks.     

Joint routing, scheduling, and power control for multichannel wireless sensor networks with physical interference

Reliability and real-time requirements bring new challenges to the energy-constrained wireless sensor networks, especially to the industrial wireless sensor networks. Meanwhile, the capacity of wireless sensor networks can be substantially increased by operating on multiple nonoverlapping channels. In this context, new routing, scheduling, and power control algorithms are required to achieve reliable and real-time communications and to fully utilize the increased bandwidth in multichannel wireless sensor networks. In this paper, we develop a distributed and online algorithm that jointly solves multipath routing, link scheduling, and power control problem, which can adapt automatically to the changes in the network topology and offered load. We particularly focus on finding the resource allocation that realizes trade-off among energy consumption, end-to-end delay, and network throughput for multichannel networks with physical interference model. Our algorithm jointly considers 1) delay and energy-aware power control for optimal transmission radius and rate with physical interference model, 2) throughput efficient multipath routing based on the given optimal transmission rate between the given source-destination pairs, and 3) reliable-aware and throughput efficient multichannel maximal link scheduling for time slots and channels based on the designated paths, and the new physical interference model that is updated by the optimal transmission radius. By proving and simulation, we show that our algorithm is provably efficient compared with the optimal centralized and offline algorithm and other comparable algorithms.     

A Hyper-Heuristic Framework for Lifetime Maximization in Wireless Sensor Networks With A Mobile Sink

Maximizing the lifetime of wireless sensor networks(WSNs) is an important and challenging research problem. Properly scheduling the movements of mobile sinks to balance the energy consumption of wireless sensor network is one of the most effective approaches to prolong the lifetime of wireless sensor networks. However, the existing mobile sink scheduling methods either require a great amount of computational time or lack effectiveness in finding high-quality scheduling solutions. To address the above issues, this paper proposes a novel hyperheuristic framework, which can automatically construct high-level heuristics to schedule the sink movements and prolong the network lifetime. In the proposed framework, a set of low-level heuristics are defined as building blocks to construct high-level heuristics and a set of random networks with different features are designed for training. Further, a genetic programming algorithm is adopted to automatically evolve promising high-level heuristics based on the building blocks and the training networks. By using the genetic programming to evolve more effective heuristics and applying these heuristics in a greedy scheme, our proposed hyper-heuristic framework can prolong the network lifetime competitively with other methods, with small time consumption. A series of comprehensive experiments, including both static and dynamic networks,are designed. The simulation results have demonstrated that the proposed method can offer a very promising performance in terms of network lifetime and response time.     

Energy-efficient multipath routing in wireless sensor network considering wireless interference

Due to the energy and resource constraints of a wireless sensor node in a wireless sensor network (WSN), design of energy-efficient multipath routing protocols is a crucial concern for WSN applications. To provide high-quality monitoring information, many WSN applications require high-rate data transmission. Multipath routing protocols are often used to increase the network transmission rate and throughput. Although large-scale WSN can be supported by high bandwidth backbone network, the WSN remains the bottleneck due to resource constraints of wireless sensors and the effects of wireless interference. In this paper, we propose a multipath energy-efficient routing protocol for WSN that considers wireless interference. In the proposed routing protocol, nodes in the interference zone of the discovered path are marked and not allowed to take part in the subsequent routing process. In this way, the quality of wireless communication is improved because the effects of wireless interference can be reduced as much as possible. The network load is distributed on multiple paths instead of concentrating on only one path, and node energy cost is more balanced for the entire wireless network. The routing protocol is simulated in NS2 software. Simulation result shows that the proposed routing protocol achieves lower energy cost and longer network lifetime than that in the literature.     

An energy-driven unequal clustering protocol for heterogeneous wireless sensor networks

Due to the limitation of energy resources, energy efficiency is a key issue in wireless sensor networks (WSNs). Clustering is proved to be an important way to realize hierarchical topology control, which can improve the scalability and prolong the lifetime of wireless sensor networks. In this paper, an energy-driven unequal clustering protocol (EDUC) for heterogeneous wireless sensor networks is proposed. EDUC includes an unequal clustering algorithm and an energy-driven adaptive cluster head rotation method. The unequal size of clusters can balance the energy consumption among clusters, and the energy-driven cluster head rotation method can achieve the balance of energy consumption among nodes within a cluster, which reduces the waste of energy. Simulation experiments show that EDUC balances the energy consumption well among the cluster heads and prolongs the network lifetime.     

Target tracking based on the extended H-infinity filter in wireless sensor networks

In this paper, we propose a new target tracking approach for wireless sensor networks (WSNs) by using the extended H-infinity filter. First, the extended H-infinity filter for nonlinear discrete-time systems is deduced through the Krein space analysis scheme. Then, the proposed extended H-infinity filtering algorithm is applied to target tracking in wireless sensor networks. Finally, experiments are conducted through a small wireless sensor network test-bed. Both experimental and simulation results illustrate that the extended H-infinity filtering algorithm is more accurate to track a moving target in wireless sensor networks than using the extended Kalman filter in the case of having no knowledge of the statistics of the environment and the target to be tracked.     

HierTrack: an energy-efficient cluster-based target tracking system forwireless sensor networks

Target tracking is a typical and important application of wireless sensor networks(WSNs).Existing target tracking protocols focus mainly on energy efficiency,and little effort has been put into network management and real-time data routing,which are also very important issues for target tracking.In this paper,we propose a scalable cluster-based target tracking framework,namely the hierarchical prediction strategy(HPS),for energyefficient and real-time target tracking in large-scale WSNs.HPS organizes sensor nodes into clusters by using suitable clustering protocols which are beneficial for network management and data routing.As a target moves in the network,cluster heads predict the target trajectory using Kalman filter and selectively activate the next round of sensors in advance to keep on tracking the target.The estimated locations of the target are routed to the base station via the backbone composed of the cluster heads.A soft handoff algorithm is proposed in HPS to guarantee smooth tracking of the target when the target moves from one cluster to another.Under the framework of HPS,we design and implement an energy-efficient target tracking system,HierTrack,which consists of 36 sensor motes,a sink node,and a base station.Both simulation and experimental results show the efficiency of our system.     

一种通用无线传感器网络Sniffer节点的设计

设计一种应用于多种无线传感器网络中的sniffer节点,给出了嗅探监听原理,分析了节点的硬件电路和软件结构的设计过程,阐述了系统中采用的CSMA／CA、WICN-Z及ZigBee通信协议,并在基于GAINS和GAINZ硬件平台的无线传感器网络中实现对网络数据的隐形监测。     

一种基于数据流跟踪的无线传感网能量模型及网络优化

提出了一种基于数据流跟踪的能量模型,通过跟踪数据流在网络中的整个过程来计算全网的能量消耗,是一种不受网络结构限制的普遍适用的能量模型;在此基础上.建立了基于能耗的网络优化模型,针对链式和簇式结构进行了拓扑、功率和路由方面的优化设计,仿真结果证明了理论分析的正确性.     

Effective target tracking mechanism in a self-organizing wireless sensor network

Target tracking is an important sensing application of wireless sensor networks. In these networks, energy, computing power, and communication bandwidth are scarce. We have considered a random heterogeneous wireless sensor network, which has several powerful nodes for data aggregation/relay and large number of energy-constrained sensor nodes that are deployed randomly to cover a given target area. In this paper, a cooperative approach to detect and monitor the path of a moving object using a minimum subset of nodes while maintaining coverage and network connectivity is proposed. It is tested extensively in a simulation environment and compared with other existing methods. The results of our experiments clearly indicate the benefits of our new approach in terms of energy consumption.     

基于RS纠删码的无线传感器网络信息分发协议性能评价

无线传感器网络中,传感器节点的能量、存储和计算能力有限,且无线传感器网络具有数据链路不对称、拓扑易变化等特点,设计节能可靠的网络协议是困难的。设计良好的网络协议不仅能降低网络的负载,还有助于节省传感器节点的能量,从而延长网络的生存周期。在无线传感器网络操作系统TinyOS平台上实现了基于RS纠删码的信息分发协议,并理论分析了在单跳情况下的协议性能,最后在仿真环境TOSSIM上模拟比较了在多跳、多路径情况下该信息分发协议和洪泛分发协议的性能。模拟仿真表明,提出的基于RS纠删码的信息分发协议明显减少了发送方发送数据包的数量,同时提高了节点的报文接收率,从而达到了降低网络能耗的目的。     

无线传感器节点实时能耗监测

无线传感器网络设计的关键技术环节之一是低功耗。首先要准确地检测到运行时各模块的能量消耗,然后才能够进行控制优化。然而,应用上的需求千差万别,导致硬件平台的多样性。本文选取无线传感器网络领域节点能量消耗检测作为研究方向,提出了一种便携的无线传感器节点能耗数据采集装置,能够实时采集节点的电压、电流信息。针对当前研究集中于仿真模拟,这种装置可用于实际环境的能量消耗检测,检测精度高。在MicaZ节点上的实验结果表明,该系统能以较高精度监测节点的能量效率。实际测量发现,传感器网络中传感器能耗也属能量消耗的一部分,且消耗量不可忽视,为今后的研究改进提供了新的参考。     

新颖的无线传感器网络组网算法

为有效解决无线传感器网络的网络维护困难性问题,研究性能更好的网络组网算法是一种有效的解决手段．本文给出了无线传感器网络体系结构模型及其连通性定义,在此基础上本文提出了一个具有网络连通性能好的无线传感器网络组网算法并进行了仿真分析,由该算法构成的无线传感器网络不仅具有连通性能好,而且具有保护网络节点能量和控制网络功率的优良特点,所以在传感器网络实际应用中有着光明的前景．     

一种新型唤醒机制的无线传感器网络节点设计

寿命过短一直困扰无线传感器网络(WSNs)与实际应用结合的难题。通过对WSNs工作效率低问题的研究,提出了一种新型射频唤醒机制的WSNs节点的设计方法,对降低节点的功耗和延长WSNs的寿命都有帮助。详细说明了节点设计的硬件结构和软件中的程序流程。可行性分析论证了节点的实用性和低功耗特性。     

面向WSN的自适应模糊功率控制算法研究

在无线传感器网络环境中存在干扰以及网络的动态变化等原因,传输可靠性问题成为保障网络服务性能的重要挑战之一。现有的研究方法基本没有考虑网络的动态性,节点能耗较高。为此,我们提出了一种面向WSN的自适应模糊功率控制算法DAFPC。该算法采用自适应模糊理论,并基于“输入-输出-反馈”机制,根据接收到的链路质量参数信息自适应地调整控制器,快速地调节发射功率。研究仿真结果表明,DAFPC算法能很好地适应网络的动态变化,有效地提高WSN的抗干扰性和传输可靠性,延长了网络的生存时间。     

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.     

无线传感网络中基于无线能量补给的能量感知路由算法

针对无线传感网络中随机分布传感器节点能量消耗不均衡的问题,提出了一种基于无线能量补给的能量感知路由算法。休眠节点不仅可以在无线携能通信(Simultaneous Wireless Information and Power Transfer,SWIPT)传输方式下通过功率分割方法进行无线能量补给,还可以在信息传输方式下通过无线能量收集方法进行能量补给,重新进入活跃状态,为信息传播提供更好的路由,提高传感器节点的能量利用,延长传感网络的使用寿命。在该算法中,通过优化节点间的信息和能量分配,最小化传输功率,引入能量路由度量方法,选择能耗最小的路径作为传输路径。仿真结果表明,本文提出的算法可以有效地利用节点资源,均衡多跳能量受限无线传感器网络中的能量分布。