无线传感器网络数据收集算法研究

对于无线传感器网络而言,可靠的数据收集是推进其大规模应用的关键,本文引入了移动传感器网络解决静态传感网络中的通信中断问题.针对移动传感器网络的数据收集,提出了数据收集的分类,分析了移动节点不同移动模式对网络数据收集的影响,比较了移动节点受控移动路径对比固定移动模式的优势,最后介绍了典型的移动节点受控移动的路径规划算法.     

Mobile-agent-based collaborative sensor fusion

Information fusion can assist in the development of sensor network applications by merging capabilities, raw data and decisions from multiple sensors through distributed and collaborative integration algorithms. In this paper, we introduce a multi-layered, middleware-driven, multi-agent, interoperable architecture for distributed sensor networks that bridges the gap between the programmable application layer consisting of software agents and the physical layer consisting of sensor nodes. We adopt an energy-efficient, fault-tolerant approach for collaborative information processing among multiple sensor nodes using a mobile-agent-based computing model. In this model the sink/base-station deploys mobile agents that migrate from node to node following a certain itinerary, either pre-determined or determined on-the-fly, and fuse the information/data locally at each node. This way, the intelligence is distributed throughout the network edge and communication cost is reduced to make the sensor network energy-efficient. We evaluate the performance of our mobile-agent-based approach as well as that of the traditional client/server-based computing model, vis-à-vis energy consumption and execution time, through both analytical study and simulation. We draw important conclusions based on our findings. Finally, we consider a collaborative target classification application, supported by our architectural framework, to illustrate the efficacy of the mobile-agent-based computing model.     

无线传感器网络时钟同步技术

在无线传感器网络中,时钟同步是一项重要的支撑技术;诸如数据融合、TDMA调度、休眠唤醒节能模式和移动节点定位等应用均需要传感器节点本地时钟保持同步;由于传感器网络一些独特的内在特性,NTP等传统同步技术无法适用于这种新型网络;因此,越来越多的研究者开始关注传感器网络时钟同步协议的研究与设计;通过回顾时钟同步的问题及传感器网络对时钟同步的需求,介绍了时钟的数学模型,并基于该模型讨论了时钟同步的3个重要概念:时钟漂移、时钟偏移和分组的传输延迟;之后简要阐述了3种专门为传感器网络设计和提出的典型传感器网络时钟同步协议.     

A Survey of Fault Management in Wireless Sensor Networks

Wireless sensor networks are resource-constrained self-organizing systems that are often deployed in inaccessible and inhospitable environments in order to collect data about some outside world phenomenon. For most sensor network applications, point-to-point reliability is not the main objective; instead, reliable event-of-interest delivery to the server needs to be guaranteed (possibly with a certain probability). The nature of communication in sensor networks is unpredictable and failure-prone, even more so than in regular wireless ad hoc networks. Therefore, it is essential to provide fault tolerant techniques for distributed sensor applications. Many recent studies in this area take drastically different approaches to addressing the fault tolerance issue in routing, transport and/or application layers. In this paper, we summarize and compare existing fault tolerant techniques to support sensor applications. We also discuss several interesting open research directions. Lilia Paradis is currently a graduate student in the Department of Mathematical and Computer Sciences, Colorado School of Mines. She is also part of the Toilers Ad Hoc Networking research group. She is interested in distributed communication protocols for wireless sensor networks. Qi Han received the PhD degree in computer science from the University of California, Irvine in 2005. She is currently an assistant professor in the Department of Mathematical and Computer Sciences, Colorado School of Mines. Her research interests include distributed systems, middleware, mobile and pervasive computing, systems support for sensor applications, and dynamic data management. She is specifically interested in developing adaptive middleware techniques for next generation distributed systems. She is a member of the IEEE and the ACM.     

无线传感器网络移动簇头节能传输协议

无线传感器网络具有资源的有限性和传感器采集数据的特点,许多在传统网络中运作良好的通信协议,在一些由固定节点和移动节点组成的无线传感器网络中不能很好地管理网络和处理传感器数据。该文提出一种移动簇头的节能通信协议,使用自组织传感器簇来处理和散发数据。通过与LEACH协议的对比,证明该协议具有更好的节能性和更长的网络寿命,更适用于无线传感器网络。     

用于移动汇聚节点的自适应数据采集策略

移动汇聚节点用于无线传感网络信息采集,可以提高网络能效性,延长网络生命期。研究了四轴飞行器携带 移动汇聚节点,该节点可采集地面无线传感网数据。通过分析汇聚节点空中移动特性,探讨了低功耗无线数据采集 时,移动轨迹、速率和高度与移动汇聚节点能够发送的数据量的之间的理论约束条件。在满足约束条件前提下,提出 基于数据量局部最优化策略,用以控制移动汇聚节点移动路径。在仿真环境中,详尽分析了这种数据采集策略下逗留 时间与移动轨迹、速度和高度等之间的关系,为这类应用莫定了理论基础。     

Improved Key Agreement Based Kerberos Protocol for M-Health Security

The development of wireless sensor network with Internet of Things (IoT) predicts various applications in the field of healthcare and cloud computing. This can give promising results on mobile health care (M-health) and Telecare medicine information systems. M-health system on cloud Internet of Things (IoT) through wireless sensor network (WSN) becomes the rising research for the need of modern society. Sensor devices attached to the patients’ body which is connected to the mobile device can ease the medical services. Security is the key connect for optimal performance of the m-health system that share the data of patients in wireless networks in order to maintain the anonymity of the patients. This paper proposed a secure transmission of M-health data in wireless networks using proposed key agreement based Kerberos protocol. The patients processed data are stored in cloud server and accessed by doctors and caregivers. The data transfer between the patients, server and the doctors are accessed with proposed protocol in order to maintain the confidentiality and integrity of authentication. The efficiency of the proposed algorithm is compared with the existing protocols. For computing 100 devices it consumes only 91milllisecond for computation.     

A testing framework for mobile computing software

We present a framework for testing applications for mobile computing devices. When a device is moved into and attached to a new network, the proper functioning of applications running on the device often depends on the resources and services provided locally in the current network. This framework provides an application-level emulator for mobile computing devices to solve this problem. Since the emulator is constructed as a mobile agent, it can carry applications across networks on behalf of its target device and allow the applications to connect to local servers in its current network in the same way as if they had been moved with and executed on the device itself. This paper also demonstrates the utility of this framework by describing the development of typical network-dependent applications in mobile and ubiquitous computing settings.     

基于 Android 智能手机的健康监护终端研究

移动通信、智能计算等技术的飞速发展和智能终端的日益普及为移动医疗的实施和广泛应用提供了机遇。本文设 计并实现一种基于 Android 手机的人体生理参数监护终端。生理信号采集传感器与手机终端之间利用蓝牙无线通讯技术组 成躯域传感器网络,实际应用表明该终端可实现对患者的监护、诊断和健康管理。     

一种模拟退火遗传算法的传感器网络数据融合技术研究

研究无线传感器网络(WSN)数据融合技术。传感器节点计算能力、通信能力有限,WSN采用交叉重叠方式部署,导致冗余数据量大,需采用数据融合技术消除冗余和无效数据,节约网络通信能耗。结合遗传算法全局搜索和模拟退火算法局部搜索的优点,提出一种模拟退火遗传算法的WSN数据融合方法(SA-GA)。采用模拟退火遗传算法快速找到移动代理路由最优传感器节点序列,并实现数据融合。仿真实验结果表明,与遗传算法、模拟退火算法相比,SA-GA更能快速找到全局最优数据融合节点序列,并对数据进行有效融合,具有更小的网络能耗和网络延时。     

基于流密码的无线传感器网络安全若干问题管窥

由设置在具体地点的大量微型传感器所组成的无线传感器网络一般是通过监控并采集特定数据,对数据进行处理,进而逐级传输到用户端的方式来实现网络通信的.鉴于无线传感器网络的自主性和独立性,其安全性能至关重要.通常情况下,无线传感器网络的储存空间以及计算能力较低,攻击漏洞明显.本文通过分析基于流密码的无线传感器网络的若干安全问题,提出一种有效的网络安全方案.     

基于移动机器人的无线传感器网络数据收集方法

稀疏无线传感器网络中各传感器节点距离较远,而传统的静态数据收集方法要求各传感器节点直接通信,导致网络延迟时间长,能耗高。针对该问题,提出一种基于移动机器人的无线传感器数据收集方法。该方法首先由静态节点选择与路径最短的移动机器人作为簇头,移动机器人比较一定周期内检测到的邻居节点的平均剩余能量与整个网络传感器节点平均剩余能量,根据比较结果决定其是否移动,若移动则采用范围可控的随机移动策略;当移动机器人移动到新位置时,传感器节点更新路由,选择新的移动机器人作为簇头。仿真结果表明,与传统的静态无线传感器网络数据收集方法相比,基于移动机器人的无线传感器网络数据收集方法大大降低了数据传输延迟和节点能量消耗。     

数据同步协议的研究和改进

随着网络的移动化趋势,嵌入式移动数据设备的应用系统越来越多,带来了更高的数据同步需求,局部数据库间以及局部数据库与数据中心间的数据的交互、交换的工作量大为增加,利用数据同步协议高效地进行数据同步成为研究重点.从可扩展性角度分析目前几种数据同步协议,并着重研究了CPISync,在保持良好的通信复杂度的基础上,对它作了改进,减少了它的立方级的计算量,更好的应用到资源受限的嵌入式移动设备的同步中.     

Energy-efficient topology control algorithm for maximizing network lifetime in wireless sensor networks with mobile sink

Uneven energy consumption is an inherent problem in wireless sensor networks characterized by multi-hop routing and many-to-one traffic pattern. Such unbalanced energy dissipation can significantly reduce network lifetime. In this paper, we study the problem of prolonging network lifetime in large-scale wireless sensor networks where a mobile sink gathers data periodically along the predefined path and each sensor node uploads its data to the mobile sink over a multi-hop communication path. By using greedy policy and dynamic programming, we propose a heuristic topology control algorithm with time complexity O(n(m + n log n)), where n and m are the number of nodes and edges in the network, respectively, and further discuss how to refine our algorithm to satisfy practical requirements such as distributed computing and transmission timeliness. Theoretical analysis and experimental results show that our algorithm is superior to several earlier algorithms for extending network lifetime.     

Distributed computing paradigms for collaborative signal and information processing in sensor networks

In this paper, we report the development of an energy-efficient, high-performance distributed computing paradigm to carry out Collaborative Signal and Information Processing (CSIP) in sensor networks using mobile agents. In this paradigm, the processing code is moved to the sensor nodes through mobile agents, in contrast to the client/server-based computing, where local data are transferred to a processing center. Although the client/server paradigm has been widely used in distributed computing, the many advantages of the mobile agent paradigm make it more suitable for sensor networks. The paper first presents simulation models for both the client/server paradigm and the mobile agent paradigm. We use the execution time, energy and energy*delay as metrics to measure the performance. Several experiments are designed to show the effect of different parameters on the performance of the paradigms. Experimental results show that the mobile agent paradigm performs much better when the number of nodes is large while the client/server paradigm is advantageous when the number of nodes is small. Based on this observation, we then propose a cluster-based hybrid computing paradigm to combine the advantages of these two paradigms. There are two schemes in this paradigm and simulation results show that there is always one scheme which performs better than either the client/server or the mobile agent paradigms. Thus, the cluster-based hybrid computing provides an energy-efficient and high-performance solution to CSIP.     

UAV-assisted data gathering in wireless sensor networks

An unmanned aerial vehicle (UAV) is a promising carriage for data gathering in wireless sensor networks since it has sufficient as well as efficient resources both in terms of time and energy due to its direct communication between the UAV and sensor nodes. On the other hand, to realize the data gathering system with UAV in wireless sensor networks, there are still some challenging issues remain such that the highly affected problem by the speed of UAVs and network density, also the heavy conflicts if a lot of sensor nodes concurrently send its own data to the UAV. To solve those problems, we propose a new data gathering algorithm, leveraging both the UAV and mobile agents (MAs) to autonomously collect and process data in wireless sensor networks. Specifically, the UAV dispatches MAs to the network and every MA is responsible for collecting and processing the data from sensor nodes in an area of the network by traveling around that area. The UAV gets desired information via MAs with aggregated sensory data. In this paper, we design a itinerary of MA migration with considering the network density. Simulation results demonstrate that our proposed method is time- and energy-efficient for any density of the network.     

移动Agent在无线传感器网络中的应用

无线传感器网络是21世纪最为重要的新兴技术之一。为解决数据是被从节点传到处理中心去处理;传感器节点密度高、数量大;节点的电池能量、计算能力存储能力严格受限;网络通信半径小、带宽低等问题,提出采用基于移动A gent的分布式计算模式,设计了一种移动A gent系统,用于实现无线传感器网络的数据融合,系统有效减少网络负载、带宽、时延,实现网络的可扩展性、可靠性和容错性。     

动态传感器网络区域受限的移动sink路径选择研究

针对sink区域受限及节点特征参数的问题,如何规划sink路径选择以满足动态传感器网络高效数据收集及低能耗的要求,提出了一种动态传感器网络区域受限的移动sink路径选择方法。该方法在缓存节点辅助通信模式下,建立sink受限区域图模型。针对不同应用情况,分别讨论了sink移动全局路径信息已知和sink移动局部路径信息已知这两种情况下的最优移动路径。在全局路径信息已知时,采用Vornon单元划分的思想求解总传输能耗和节点平均负载;在局部路径信息已知时,采用启发式策略进行路径寻优,并证明其路径寻优的正确性。最后通过仿真实验与理论计算来验证移动sink最佳路径寻优策略的有效性和可行性。     

Design and implementation of the secure compiler and virtual machine for developing secure IoT services

Recent years have seen the development of computing environments for IoT (Internet of Things) services, which exchange large amounts of information using various heterogeneous devices that are always connected to networks. Since the data communication and services occur on a variety of devices, which not only include traditional computing environments and mobile devices such as smartphones, but also household appliances, embedded devices, and sensor nodes, the security requirements are becoming increasingly important at this point in time. Already, in the case of mobile applications, security has emerged as a new issue, as the dissemination and use of mobile applications have been rapidly expanding. This software, including IoT services and mobile applications, is continuously exposed to malicious attacks by hackers, because it exchanges data in the open Internet environment. The security weaknesses of this software are the direct cause of software breaches causing serious economic loss. In recent years, the awareness that developing secure software is intrinsically the most effective way to eliminate the software vulnerability, rather than strengthening the security system of the external environment, has increased. Therefore, methodology based on the use of secure coding rules and checking tools is attracting attention to prevent software breaches in the coding stage to eliminate the above vulnerabilities. This paper proposes a compiler and a virtual machine with secure software concepts for developing secure and trustworthy services for IoT environments. By using a compiler and virtual machine, we approach the problem in two stages: a prevention stage, in which the secure compiler removes the security weaknesses from the source code during the application development phase, and a monitoring stage, in which the secure virtual machine monitors abnormal behavior such as buffer overflow attacks or untrusted input data handling while applications are running.     

无线传感器网络便携式用户接口的设计与实现

重点考察无线传感器网络的人机交互问题,设计并实现了一种基于手持移动设备的无线传感器网络用户接口,以方便人们对传感器网络节点的灵活访问与控制。该用户接口搭建于Pocket PC平台,通过蓝牙与汇聚节点进行双向通信,从而实现对整个无线传感器网络系统的监控。用户可以通过便携式接口现场采集与处理传感器网络节点的数据,同时也可以发送指令对汇聚节点和普通节点进行各种设置。演示实验结果验证了该接口系统的可行性与有效性。