无线传感器网络环境下基于事件 驱动应用的节能TDMA协议

媒质接入控制是无线传感器网络设计的关键问题之一.由于媒质接入控制协议直接控制着节点无线通信模块的活动,而无线通信模块是传感器节点能量消耗的主要来源,因此MAC协议节能效率的好坏将严重影响网络的性能.基于TDMA的MAC协议具有固有的节能特性,即通过合理的TDMA调度避免传输碰撞以及减少节点空闲监听的时间.本文提出了ED-TDMA协议,一种面向事件驱动的传感器网络应用的TDMA协议.该协议根据当前源节点的数目动态地改变TDMA帧的长度,提高了信道利用率;同时采用位图方式的TDMA调度,极大地减少了TDMA调度的开销,节约了能量.此外,通过引入簇内覆盖的思想,使得簇内的活动节点数目为一常数,同时减少了工作节点的数目,从而延长网络的生命周期,并在一定程度上提高了系统的可伸缩性.实验结果显示,ED-TDMA协议更适用于网络负载较低、节点密度高的无线传感器网络.     

一种能量均衡的无线传感器网络协议

提出了一种能量均衡的无线传感器网络协议。在此协议中,用以基站为圆心一定距离为半径的环状带将目标网络覆盖区域分为三部分,靠近圆心的节点和环状带内节点采用单跳方式直接跟基站通信,环状带以外的节点采用多跳方式跟环状带内节点通信;节点保存多条到基站的最短路由,采用轮循机制选择一条路由传输数据,从而将数据传输任务均衡的分配到多条线路上;当环状带内节点的能量值达到一个阀值时修改环状带的半径和宽度,重新组网,从而将即将形成的"热区"转移到其他区域,达到延长无线传感器网络的生命周期。     

高能量有效性的无线传感器网络 数据收集和路由协议

 提出了一种分布式高效节能的无线传感器网络数据收集和路由协议HEEDC.此协议中传感器节点根据自身状态(综合考虑剩余能量、节点密度等因素计算得出的代价因子)自主的竞争簇首,同时为减少簇首节点的能量开销,簇首之间通过多跳方式将各个簇内收集到的数据发送给特定簇首节点,并由此簇首节点将整个网络收集的数据发送给汇聚节点.仿真实验表明,HEEDC协议比起现有的几种重要路由协议(如LEACH、PEGASIS等),能提供更加有效的能量使用效率,延长无线传感器网络的生存周期.因此,使用HEEDC协议的无线传感器网络具有更好的使用性,其监测结果具有更高的可靠性.     

无线传感器网络阈值敏感的按需路由算法

针对路由算法对无线传感器网络wsn的能效影响很大,将AODV协议和TEEN协议进行优势组合并加以改进,提出一个阈值敏感的移动式基站按需路由算法.算法通过设置门限值和数据聚合减少了数据的传输,提高了网络的能效;采用移动式基站并配合按需路由,平衡了整个网络的能量消耗并节省了内存开销;采取CSMA传输方式和故障自动修复等方法,确保了网络的吞吐量.通过对网络能耗和活跃节点数进行仿真实验,结果表明,该算法具有优秀的综合性能.     

DEED:一种无线传感器网络中高效节能的数据通信协议

无线传感器网络由许多具有低功率无线收发装置的传感器节点组成,能够有效地从不同环境监测收集周边环境信息并传送到远处的基站进行处理.由于传感器节点的电池能量极为有限,因此节点的通信应有效的利用能量,以延长网络的生命周期.LEACH^[4]协议是一种典型的能有效延长网络生命周期的节能通信协议.本文提出了一种分布的、高效节能的通信协议DEED,DEED利用了数据聚合技术,以聚类的方式组织节点,聚类首领在网络中均匀分布并组织成路由树,由根节点与基站直接通信.实验结果显示DEED性能远好于LEACH.     

一种大规模无线传感器网络的协议框架、网络结构和能耗分析

本文定义了一种适用于大范围数据采集的传感器网络构架DMCH(Directed Multi-Hop Clustering Hierarchy)及相关的媒体接入层和网络层协议,并建立数学模型对该网络结构和能耗状况进行了分析.DMCH通过预先设置在网络探测区域内的功能较强的小基站,将网络划分为分布相对均匀的群,在每个群内又将节点分级,形成分群多级的结构.同时,采用小基站轮流作群首的策略,保证了网络能耗的均衡性.DMCH具有可扩展性强、能耗均匀、协议简单、成本低、连通性好等特点.仿真结果为网络结构和能耗分析提供了依据并验证了各项设计指标,通过仿真与典型的大规模传感器网络协议MINA(Multi-Hop infrastructure Network Architecture)对比显示了DMCH在能耗及可扩展性等方面的优越性.     

一种无线传感网络代码分发协议的研究

无线传感器网络的分发协议用于更新节点程序和发送控制指令,目前普遍采用的分发协议存在传输数据量和能耗过大的问题.为此提出一种无线传感网络代码传播与维护的自调整算法,并通过设计分发协议测试系统进行算法性能测试.实验结果表明该算法能有效调节网络中数据包的传输速度,减少数据包传输量,降低能量损耗.     

大规模无线传感器网络分簇路由协议改进方案

本文对大规模无线传感器网络的路由协议进行了研究,提出一种全新的高能效分簇路由协议.根据节点数目以及分布区域大小,通过数学公式推导得出最优的簇首节点数目.对簇首进行改进,均衡网络的负载,减少节点的过早死亡,延长整个网络的寿命.离基站较远的簇首利用多跳来传输数据,减少远距离簇首的能量消耗,延长网络寿命,使网络规模不受限.使用Matlab软件进行仿真实验,实验结果表明新协议能够均衡网络节点能耗,延长网络生命时间,且能适用于大规模的网络.     

基于分簇的MACA协议改进算法

针对大规模水声传感器网络,本文提出一种新的MACA协议改进算法,将TDMA协议与MACA协议进行融合,对整个大规模传感器网络的节点进行分簇,簇内通信和簇首通信采用不同的协议:一种更加适合簇内小规模网络的TDMA协议;一种更加适合长距离多数据的MACA协议.改进MACA协议预约方式和数据传输方式,使其更加适应复杂的信道.同时使它们工作在不同的频段上,防止干扰以及不需要对整个网络节点进行时间同步.     

移动代理在MANET路由协议中的应用研究

移动Ad Hoc网络(MANET)是由移动节点组成的分布式异构网络,其路由协议的研究是该领域的焦点之一。本文分析了现有移动Ad Hoc网络两类路由协议的优缺点,接着提出将移动代理应用于AODV路山协议的方案,最后给出了初步的仿真结果。仿真结果表明,通过移动代理的漫游更新途经节点路由表,可以在网络负载增加不人的情况下,减少路由发起数,降低端到端的数据传输延迟。     

无线传感器网络中移动sink节点的路径规划

在无线传感器网络中,大量感知数据汇集到sink节点的采集方法会导致sink节点附近的节点能量耗尽,造成能量空洞。针对该问题,利用移动的sink节点进行数据收集是一种解决方法,其中移动sink的路径规划成为一个重要的问题。提出了一个移动sink路径规划算法,将无线传感器中随机分布的节点划分为不同的子区域,寻找sink节点移动的最佳转向点,最终得到最优的移动路径,以实现无线传感器网络生命周期最大化。仿真实验表明,与现有方案相比,该算法能显著延长网络的生命周期。     

Data Aggregation using Difference transfer for Load Reduction in Periodic Sensor Networks

One of the basic challenges in wireless sensor networks is energy conservation. Sensor nodes are energy constrained and prudent energy usage is of utmost importance. Data aggregation aims to reduce amount of data communicated across the network without loss in information, thereby reducing the energy costs, and increasing network lifetime. In this paper, we propose a novel, simple and easy to implement method to reduce the amount of periodic data transferred from the sensor nodes to the sink. Instead of sending a set of measures at the end of every time period, we propose sending the first measure, and for every subsequent measure in that time period, we send the difference with respect to first measure. Differences are represented by a group of binary bits. Differences are also chosen in an adaptive manner in order to maintain precision between the data measured at sensor nodes and data reconstructed from binary bit patterns at sink. We evaluated our technique against two real world data-sets with vastly different properties. Results indicate 85–88.5% reduction in amount of data sent and transmission energy.

     

Novel service protocol for supporting remote and mobile users in wireless sensor networks with multiple static sinks

A wireless sensor network typically consists of users, a sink, and a number of sensor nodes. The users may be remotely connected to a wireless sensor network and via legacy networks such as Internet or Satellite the remote users obtain data collected by the sink that is statically located at a border of the wireless sensor network. However, in practical sensor network applications, there might be two types of users: the traditional remote users and mobile users such as firefighters and soldiers. The mobile users may move around sensor fields and they communicate with the static sink only via the wireless sensor networks in order to obtain data like location information of victims in disaster areas. For supporting the mobile users, existing studies consider temporary structures. However, the temporary structures are constructed per each mobile user or each source nodes so that it causes large energy consumption of sensor nodes. Moreover, since some of them establish the source-based structure, sinks in them cannot gather collective information like mean temperature and object detection. In this paper, to effectively support both the remote users and the mobile users, we propose a novel service protocol relying on the typical wireless sensor network. In the protocol, multiple static sinks connect with legacy networks and divide a sensor field into the number of the multiple sinks. Through sharing queries and data via the legacy networks, the multiple static sinks provide high throughput through distributed data gathering and low latency through short-hops data delivery. Multiple static sinks deliver the aggregated data to the remote users via the legacy networks. In case of the mobile users, when a mobile user moves around, it receives the aggregated data from the nearest static sink. Simulation results show that the proposed protocol is more efficient in terms of energy consumption, data delivery ratio, and delay than the existing protocols.     

DDRP: An efficient data‐driven routing protocol for wireless sensor networks with mobile sinks

Introduction of mobile sinks into a wireless sensor network can largely improve the network performance. However, sink mobility can cause unexpected changes of network topology, which may bring excessive protocol overhead for route maintenance and may offset the benefit from using mobile sinks. In this paper, we propose an efficient data‐driven routing protocol (DDRP) to address this problem. The design objective is to effectively reduce the protocol overhead for data gathering in wireless sensor networks with mobile sinks. DDRP exploits the broadcast feature of wireless medium for route learning. Specifically, each data packet carries an additional option recording the known distance from the sender of the packet to target mobile sink. The overhearing of transmission of such a data packet will gratuitously provide each listener a route to a mobile sink. Continuous such route‐learning among nodes will provide fresh route information to more and more nodes in the network. When no route to mobile sink is known, random walk routing simply is adopted for data packet forwarding. Simulation results show that DDRP can achieve much lower protocol overhead and longer network lifetime as compared with existing work while preserving high packet delivery ratio. Copyright © 2012 John Wiley & Sons, Ltd.     

时延受限的移动sink数据收集算法

在实时性要求比较高的应用中,时延要求限制了sink的移动速率与移动轨迹,sink的移动速率限制了节点与sink的通信时间,因此很难兼顾时延要求与数据收集效率。提出一种时延受限的移动sink数据收集算法MSDC,在低能耗缓存区内找到一条sink的最优移动轨迹,在有限的时间限制内利用sink的移动性来提升传感器网络的数据收集性能。仿真结果表明,与已有算法比较,该方案能够提高网络数据采集量,降低能耗,延长网络生命周期。     

Minimum spanning tree–based delay‐aware mobile sink traversal in wireless sensor networks

Energy efficient data collection in a delay‐bound application is a challenging issue for mobile sink–based wireless sensor networks. Many researchers have proposed the concept of rendezvous points (RPs) to design the path for the mobile sink. Rendezvous points are the locations in the network where the mobile sink halts and collects data from the nearby sensor nodes. However, the selection of RPs for the design of path has a significant impact on timely data collection from the network. In this paper, we propose an efficient algorithm for selection of the RPs for efficient design of mobile sink trajectory in delay‐bound applications of wireless sensor networks. The algorithm is based on a virtual path and minimum spanning tree and shown to maximize network lifetime. We perform extensive simulations on the proposed algorithm and compare results with the existing algorithms to demonstrate the efficiency of the proposed algorithm of various performance metrics.     

Energy-Aware Data Aggregation for Grid-Based Wireless Sensor Networks with a Mobile Sink

Wireless sensor networks (WSNs) are made up of many small and highly sensitive nodes that have the ability to react quickly. In WSNs, sink mobility brings new challenges to large-scale sensor networks. Almost all of the energy-aware routing protocols that have been proposed for WSNs aim at optimizing network performance while relaying data to a stationary gateway (sink). However, through such contemporary protocols, mobility of the sink can make established routes unstable and non-optimal. The use of mobile sinks introduces a trade-off between the need for frequent rerouting to ensure optimal network operation and the desire to minimize the overhead of topology management. In this paper, in order to reduce energy consumption and minimize the overhead of rerouting frequency, we propose an energy-aware data aggregation scheme (EADA) for grid-based wireless sensor networks with a mobile sink. In the proposed scheme, each sensor node with location information and limited energy is considered. Our approach utilizes location information and selects a special gateway in each area of a grid responsible for forwarding messages. We restrict the flooding region to decrease the overhead for route decision by utilizing local information. We conducted simulations to show that the proposed routing scheme outperforms the coordination-based data dissemination scheme (CODE) (Xuan, H. L., & Lee, S. Proceedings of the Sensor Networks and Information Processing Conference, pp. 13–18, 2004).     

Energy-efficient target detection in sensor networks using line proxies

One of the fundamental and important operations in sensor networks is sink–source matching, i.e. target detection. Target detection is about how a sink finds the location of source nodes observing the event of interest (i.e. target activity). This operation is very important in many sensor network applications such as military battlefield and environment habitats. The mobility of both targets and sinks brings significant challenge to target detection in sensor networks. Most existing approaches are either energy inefficient or lack of fault tolerance in the environment of mobile targets and mobile sinks. Motivated by these, we propose an energy-efficient line proxy target detection (LPTD) approach in this paper. The basic idea of LPTD is to use designated line proxies as rendezvous points (or agents) to coordinate mobile sinks and mobile targets. Instead of having rendezvous nodes for each target type as used by most existing approaches, we adopt the temporal-based hash function to determine the line in the given time. Then the lines are alternated over time in the entire sensor network. This simple temporal-based line rotation idea allows all sensor nodes in the network to serve as rendezvous points and achieves overall load balancing. Furthermore, instead of network-wide flooding, interests from sinks will be flooded only to designated line proxies within limited area. The interest flooding can further decrease if the interest has geographical constraints. We have conducted extensive analysis and simulations to evaluate the performance of our proposed approach. Our results show that the proposed approach can significantly reduce overall energy consumption and target detection delay. Copyright © 2007 John Wiley & Sons, Ltd.     

A myopic mobile sink migration strategy for maximizing lifetime of wireless sensor networks

Network lifetime maximization is challenging particularly for large-scale wireless sensor networks. The sensor nodes near the sink node tend to suffer high energy consumption due to heavy traffic relay operations, becoming vulnerable to energy depletion. The rationale of the sink mobility approach is that as the sink node moves around, such risk of energy depletion at some nodes can be alleviated. In this paper, we first obtain the optimal mobile sink sojourning pattern by solving a linear programming model and then we mathematically analyze why the optimal solution exhibits such sojourning pattern. We use the insights from this analysis to design a simple practical heuristic algorithm for sink mobility, which utilizes only local information. Our heuristic is very different from the existing algorithms which often use the traffic volume as the main decision factor, in that we consider the variance of residual energy of neighboring sensor nodes. The simulation results show that our scheme achieves near-optimal network lifetime even with the relatively low moving speed of the mobile sink.     

无线传感网络中基于蚁群的路由算法

In the wireless sensor networks, high efficient data routing for the limited energy resource networks is an important issue. By introducing Ant-colony algorithm, this paper proposes the wireless sensor network routing algorithm based on LEACH. During the construction of sensor network clusters, to avoid the node premature death because of the energy consumption, only the nodes whose residual energy is higher than the average energy can be chosen as the cluster heads. The method of repeated division is used to divide the clusters in sensor networks so that the numbers of the nodes in each cluster are balanced. The basic thought of ant-colony algorithm is adopted to realize the data routing between the cluster heads and sink nodes, and the maintenance of routing. The analysis and simulation showed that the proposed routing protocol not only can reduce the energy consumption, balance the energy consumption between nodes, but also prolong the network lifetime.