无线传感器网络及其在环境监测应用概况

概述了无线传感器网络,简要介绍了无线传感器网络的体系结构及无线传感器网络的若干重要协议,分析了无线传感器网络在贵重武器及农作物环境监测中的一些应用概况。对无线传感器网络的核心问题之一-电能问题进行了探讨。最后对无线传感器网络在环境监测应用中的一些概况进行了展望。     

无线传感器网络的体系结构

在对无线传感器应用特征进行分析的基础上,总结了无线传感器体系结构设计的要素,讨论了无线传感器网络的二维体系结构和组网方式.通过与传统Ad hoc网络的对比,归纳了无线传感器网络在各层各面设计的特点.文章认为虽然传统的传感器的应用方向主要在军事领域,但在民用领域也存在着广阔的前景.     

无线传感器网络在医疗中的应用

首先简介无线传感器网络的体系结构以及无线传感器网络在医疗中的应用情况,接着对无线传感器网络医疗监护系统的体系结构以及监护节点的设计进行阐述,最后,阐述无线传感器网络应用到医疗监护时存在的挑战。     

无限传感器网络综述

近十几年来无线传感器网络技术取得了飞速的发展.本文通过介绍无线传感器网络的体系结构与传统Adhoc网络相比分析了无线传感器网络的独特性.并且从无线传感器网络的特性出发,分析了其广阔的应用前景.     

无线传感器网络综述

近十几年来,无线传感器网络技术取得了飞速的发展。本文通过介绍无线传感器网络的体系结构,与传统Ad hoc网络相比,分析了无线传感器网络的独特性。并且从无线传感器网络的特性出发,分析了其广阔的应用前景。     

无线传感器网络时间同步优化算法的研究

本文主要围绕着无线传感器网络时间同步问题展开分析，具体分析了无线传感器网络体系的基本原理和和体系结构，进而分析了无线传感器网络时间同步优化的一些算法和新技术。     

无线传感器网络关键技术及其研究难点

本文在简要介绍无线传感器网络特点的基础上,给出了无线传感器网络的体系结构,在此体系结构下,系统地阐述了无线传感器网络的研究现状,并指出了尚存在的难点和可能的研究方向.     

无线传感器网络热点问题的研究

无线传感器网络作为信息科学领域中一个全新的发展方向,以其巨大的应用前景引起了学术界和工业界的广泛关注。本文介绍了无线传感器网络的研究热点,包括无线传感器的概念、体系结构、通信协议、传感器网络管理、应用支撑,最后对无线传感器的研究进行展望。     

无线传感器网络技术研究初探

无线传感器网络技术是一种全新的信息获取和处理技术。介绍了无线传感器网络的概念、典型体系结构、协议层次结构及主要特点,分析和展望了一些有价值的应用领域,简要总结了国内外的研究动态,最后重点分析和阐述了无线传感器网络的主要研究内容,希望能对进行或将要进行这方面研究的人们有所启发和帮助。     

无线传感器网络与传统Ad Hoc网络的比较研究

近年来，无线通信和电子技术的进步促进了Ad Hoe网络的发展，无线传感器网络是Ad Hoe网络的几大应用领域之一，但与传统Ad Hoe网络比有差异，传统Ad Hoe网络的协议大部分都不适合于无线传感器网络，文中从体系结构、协议栈和应用方面对无线传感器网络和传统Ad Hoe网络进行比较和分析。     

无线传感反应网络中反应节点协调机制研究

从传感器网络衍生出来的传感反应网络是一种全新的信息获取和处理技术。这里简要介绍了传感反应网络的体系结构,讨论了无线传感反应网络中反应节点之间的协调以及任务分配机制。在单反应节点任务的分布式协调机制的基础上,运用多目标进化算法设计出了多反应节点的协调算法,为进一步提高系统效能提供了一种新的思路。     

Intelligent actor mobility in wireless sensor and actor networks

In wireless sensor and actor network research, the commonly used mobility models for a mobile actor are random walk model, random waypoint mobility model, or variants thereof. For a fully connected network, the choice of mobility model for the actor is not critical because, there is at least one assured path from the sensor nodes to the actor node. But, for a sparsely connected network where information cannot propagate beyond a cluster, random movement of the actor may not be the best choice to maximize event detection and subsequent action. This paper presents static and dynamic intelligent mobility models that are based on the inherent clusters’ information of a sparsely connected network. Simulation results validate the idea behind the intelligent mobility models and provide insights into the applicability of these mobility models in different application scenarios.     

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.     

Detecting and connecting disjoint sub-networks in wireless sensor and actor networks

Wireless sensor and actor networks (WSANs) can be considered as a combination of a sensor network and an actor network in which powerful and mobile actor nodes can perform application specific actions based on the received data from the sensors. As most of these actions are performed collaboratively among the actors, inter-actor connectivity is one of the desirable features of WSANs. In this paper, we propose a novel distributed algorithm for establishing a connected inter-actor network topology. Considering initially disjoint sets of actors, our algorithm first initiates a search process by using the underlying sensor network in order to detect the possible sub-networks of actors in the region. After these sub-networks are detected, our algorithm pursues a coordinated actor movement in order to connect the sub-networks and thus achieve inter-actor connectivity for all the actors. This coordinated movement approach exploits the minimum connected dominating set of each sub-network when picking the appropriate actor to move so that the connectivity of each sub-network is not violated. In addition, the approach strives to minimize the total travel distance of actors and the messaging cost on both sensors and actors in order to extend the lifetime of WSAN. We analytically study the performance of our algorithm. Extensive simulation experiments validate the analytical results and confirm the effectiveness of our approach.     

Greedy algorithms for actor redeployment in wireless sensor–actor networks

In a wireless sensor–actor network, an actor usually has to provide services as soon as the actor receives the event signals from the sensors. Therefore, the performance of a wireless sensor–actor network depends on the actor deployment. In many circumstances, actors may fail or go out to deal with events, and thus, the sensors covered by the missing actors could be not to be reachable in time. This introduces the necessity of actor redeployment. In this paper, we study the problems of redeploying actors to maximize the number of sensors able to be covered by actors and to maximize the decrease of the residual distances of sensors, respectively. Both problems are shown to be NP-complete. Additionally, we prove that the greedy algorithm for each problem has an approximation ratio of 2. Simulations show that the greedy algorithm for each problem performs well.     

Path scheduling for multiple mobile actors in wireless sensor network

In wireless sensor network (WSN), energy is the main constraint. In this work we have addressed this issue for single as well as multiple mobile sensor actor network. In this work, we have proposed Rendezvous Point Selection Scheme (RPSS) in which Rendezvous Nodes are selected by set covering problem approach and from that, Rendezvous Points are selected in a way to reduce the tour length. The mobile actors tour is scheduled to pass through those Rendezvous Points as per Travelling Salesman Problem (TSP). We have also proposed novel rendezvous node rotation scheme for fair utilisation of all the nodes. We have compared RPSS with Stationery Actor scheme as well as RD-VT, RD-VT-SMT and WRP-SMT for performance metrics like energy consumption, network lifetime, route length and found the better outcome in all the cases for single actor. We have also applied RPSS for multiple mobile actor case like Multi-Actor Single Depot (MASD) termination and Multi-Actor Multiple Depot (MAMD) termination and observed by extensive simulation that MAMD saves the network energy in optimised way and enhance network lifetime compared to all other schemes.     

Network Partitioning Recovery Mechanisms in WSANs: a Survey

Wireless sensor and actor networks (WSANs) are more promising and most addressing research field in the area of wireless sensor networks in recent scenario. It composed of possibly a large number of tiny, autonomous sensor devices and resources rich actor nodes equipped with wireless communication and computation capabilities. Actors collect sensors’ information and respond collaboratively to achieve an application specific mission. Since actors have to coordinate their operation, a strongly connected inter-actor network would be required at all the time in the network. Actor nodes may fail for many reasons (i.e. due of battery exhaustion or hardware failure due to hash environment etc.) and failures may convert connected network into disjoint networks. This can hinder sometimes not only the performance of network but also degrade the usefulness and effectiveness of the network. Thus, having a partitioning detection and connectivity restoration procedure at the time of failure occurs in the network is crucial for WSANs. In this paper, we review the present network partitioning recovery approaches and provide an overall view of this study by summarizing previous achievements.     

基于OMAPLl38芯片的无线传感器网络节点设计

随着传感器技术、无线网络技术的迅速发展,无线传感器网络在军事和商业领域有着广泛的应用前景。无线传感器网络中的节点具有感知和路由的功能,是构成无线传感器网络的基本单元。针对传感器节点的特点,基于双核架构OMAPLl38为核心设计了一种低功耗高性能无线传感器节点。在介绍OMAPLl38的基础上,详细阐述了传感器节点设计及实现过程,包括硬件体系结构和软件开发流程,提出一种无线传感器网络节点设计方案。该方案可广泛应用于其他区域的无线传感器网络构建。     

Adaptive Pull�CPush Based Event Tracking in Wireless Sensor Actor Networks

Wireless sensor networks have attracted significant interest for various scientific, military, and e-health applications. Recently a new class of sensor networks ??sensor/actor networks?? has been introducing new research challenges due to the unique coordination requirements among sensors and actors. In sensor/actor networks, actors are the nodes that have the capability to move in the field, equipped with powerful devices and can respond to the events of interest. With this capability, autonomous operation of the network is possible without a centralized controlling mechanism. This, however, requires the network to apply cooperative mechanism to decide when and how monitoring is done to track the event and how the event will be responded. In this regard, little work has been done in terms of co-existing Push and Pull data flows in the network. In this paper, we propose an Adaptive Pull?CPush (APP) based Event Tracking approach that allows sensor-to-actor communication as well as actors coordination in response to the events occurred. APP proposes two models of sensors organization: region-based organization (RAPP) and neighbor-based organization (NAPP) to alert nodes in the vicinity of reported event. APP exploits the mobility of actor nodes to form dynamic responsibility clusters, thus ensuring an event specific response to emergencies. Routing in APP is based on Routing by Adaptive Targeting (RAT), which is a delay-constrained geographical routing protocol. Simulation results reveal significant performance improvement in terms of response time and energy conservation.