Application-aware integration of data collection and power management in wireless sensor networks

Sensors are typically deployed to gather data about the physical world and its artifacts for a variety of purposes that range from environment monitoring, control, to data analysis. Since sensors are resource constrained, often sensor data is collected into sensor databases that reside at (more powerful) servers. A natural tradeoff exists between resources (bandwidth, energy) consumed and the quality of data collected at the server. Blindly transmitting sensor updates at a fixed periodicity to the server results in a suboptimal solution due to the differences in stability of sensor values and due to the varying application needs that impose different quality requirements across sensors. In order to adapt to these variations while at the same time optimizing the energy consumption of sensors, this paper proposes three different models and corresponding data collection protocols. We analyze all three models with a Markov state machine formulation, and either derive closed forms for the operation point of the data collection application or suggest algorithms for estimating this operating point to achieve a minimal energy consumption. We observe that the operating point depends on environmental characteristics and application quality requirements, which the proposed algorithms aim to accommodate. Our experimental results show significant energy savings compared to the naive approach to data collection.     

工业生产实时数据采集及管理数据库模型设计

提出了中小型生产企业在企业信息化过程中的生产数据实时采集、安全存储、有效管理的重要性,并给出生产数据的自动统计、分析、处理及为企业的生产经营提供决策的手段。     

Topology control for delay-constraint data collection in wireless sensor networks

Data collection is one of the most important operations in wireless sensor networks. Many practical applications require the real-time data transmission, such as monitoring, tracking, etc. In this paper, we import and define the topology control problem for delay-constraint data collection (TDDC), and then formalize this problem into an integer programming problem. As NP-Hardness of this problem, we present a load-aware power-increased topology control algorithm (namely LPTC) to heuristically solve the problem. The theoretical analysis shows that this algorithm can reach O(1)-approximation ratio for the linear networks. And we also analyze the impact of the delay-constraint on the worst-case for the planar networks. Moreover, this paper designs two localized algorithms, called as SDEL and DDEL, based on the area division for TDDC problem. The experimental results show that LPTC algorithm can save at least 17% power consumptions compared with HBH algorithm in many situations.     

A wireless sensor networks MAC protocol for real-time applications

Wireless sensor networks (WSN) are designed for data gathering and processing, with particular requirements: low hardware complexity, low energy consumption, special traffic pattern support, scalability, and in some cases, real-time operation. In this paper we present the virtual TDMA for sensors (VTS) MAC protocol, which intends to support the previous features, focusing particularly on real-time operation. VTS adaptively creates a TDMA arrangement with a number of timeslots equal to the actual number of nodes in range. Thus, VTS achieves an optimal throughput performance compared to TDMA protocols with fixed size of frame. The frame is set up and maintained by a distributed procedure, which allows sensors to asynchronously join and leave the frame. In addition, duty cycle is increased or decreased in order to keep latency constant below a given deadline. Therefore, a major advantage of VTS is that it guarantees a bounded latency, which allows soft real-time applications.

串行通信在实时数据采集中的应用

本文讨论了VB 6.0 MSComm控件在数据采集中的应用。利用VB6.0 ActiveX中的MSComm通信控件,实现了Windows下单台PC机与多台计量仪表的串行通信,达到了以较低的硬件成本对多路数据自动采集、计算和分析的目的。     

Support for real-time decision making in mobile financial applications

Mobile users making real-time decisions based on current information need confidence that their context has been taken into consideration in producing the system’s recommendations. This chapter reviews current use of mobile technologies for context-aware real-time decision support. Specifically, it describes a framework for assessing the impact of mobility in decision making. The framework uses dynamic context model of data quality to represent uncertainties in the mobile decision-making environment. This framework can be used for developing visual interactive displays for communicating to the user relevant changes in data quality when working in mobile environments. As an illustration, this chapter proposes a real-time decision support procedure for on-the-spot assistance to the mobile consumer when choosing the best payment option to efficiently manage their budget. The proposed procedure is based on multi-attribute decision analysis, scenario reasoning, and a quality of data framework. The feasibility of the approach is demonstrated with a mobile decision-support system prototype implementation. This article is part of the “Handbook on Decision Support Systems” edited by Frada Burstein and Clyde W. Holsapple (2008) Springer.     

A distributed energy-efficient clustering protocol for wireless sensor networks

Minimizing energy dissipation and maximizing network lifetime are among the central concerns when designing applications and protocols for sensor networks. Clustering has been proven to be energy-efficient in sensor networks since data routing and relaying are only operated by cluster heads. Besides, cluster heads can process, filter and aggregate data sent by cluster members, thus reducing network load and alleviating the bandwidth. In this paper, we propose a novel distributed clustering algorithm where cluster heads are elected following a three-way message exchange between each sensor and its neighbors. Sensor’s eligibility to be elected cluster head is based on its residual energy and its degree. Our protocol has a message exchange complexity of O(1) and a worst-case convergence time complexity of O(N). Simulations show that our algorithm outperforms EESH, one of the most recently published distributed clustering algorithms, in terms of network lifetime and ratio of elected cluster heads.     

Analysis of smartphone user mobility traces for opportunistic data collection in wireless sensor networks

The increasing ubiquity of smartphones coupled with the mobility of their users will allow the use of smartphones to enhance the operation of wireless sensor networks. In addition to accessing data from a wireless sensor network for personal use, and the generation of data through participatory sensing, we propose the use of smartphones to collect data from sensor nodes opportunistically. For this to be feasible, the mobility patterns of smartphone users must support opportunistic use. We analyze the dataset from the Mobile Data Challenge by Nokia, and we identify the significant patterns, including strong spatial and temporal localities. These patterns should be exploited when designing protocols and algorithms, and their existence supports the proposal for opportunistic data collection through smartphones.     

Poly: A reliable and energy efficient topology control protocol for wireless sensor networks

Energy efficiency and reliability are the two important requirements for mission-critical wireless sensor networks. In the context of sensor topology control for routing and dissemination, Connected Dominating Set (CDS) based techniques proposed in prior literature provide the most promising efficiency and reliability. In a CDS-based topology control technique, a backbone - comprising a set of highly connected nodes - is formed which allows communication between any arbitrary pair of nodes in the network. In this paper, we show that formation of a polygon in the network provides a reliable and energy-efficient topology. Based on this observation, we propose Poly, a novel topology construction protocol based on the idea of polygons. We compare the performance of Poly with three prominent CDS-based topology construction protocols namely CDS-Rule K, Energy-efficient CDS (EECDS) and A3. Our simulation results demonstrate that Poly performs consistently better in terms of message overhead and other selected metrics. We also model the reliability of Poly and compare it with other CDS-based techniques to show that it achieves better connectivity under highly dynamic network topologies.     

一种海洋传感器的电力线载波数据采集传输系统

针对电力线载波技术在数据传输中的应用,研究并改进了现有的基于220VAC电力线载波技术,实现了一种基于500VAC电力线载波模块,设计了基于500VAC船载数据采集传输系统,以获取海洋船载5路阻性负载的电压电流值和15路液压值,同时设计500VAC输出可控电路,以降低水下模块功耗。系统以STM32F107处理器为核心,以改进的500VAC电力线载波模块为数据收发模块,在应用上实现了船载数据采集、传输和误码率的测试。经测试,能可靠地将数据传输到上位机,满足了设计要求。     

基于规则的数据收集研究

企业的业务子系统繁多、数据结构复杂,导致对企业基础数据的再利用十分困难,从根本上体现为跨系统的数据收集困难.为此提出基于规则的数据收集策略,将数据收集过程分成"共性"和"特性"两种情况.对于"共性"的情况,提炼出若干规则,并形成规则集;对于"特性"的情况,将其开放出来便于定制开发.在实际应用中,利用其规则集组合实现复杂环境下(多应用系统)的数据收集.     

基于LwIP的海洋数据采集与传输系统

针对海洋数据采集系统中串行数据传输能力不能满足海洋环境实时监测需求的现状,设计并实现了一种传输速率较高的以太网数据传输系统.系统以STM32F207VGT6处理器为核心,选择轻量级的LwIP作为以太网协议栈,将LwIP TCP/IP协议栈移植到STM32F207VGT6上,在应用层实现了一个网络、串口数据双向传输的数据传输系统.经测试,其传输速率优于同条件下RS232、RS485、CAN总线的传输速度,满足了设计要求.     

TPS3: A privacy preserving data collection protocol for smart grids

Smart grid (SG) allows for two-way communication between the utility and its consumers and hence they are considered as an inevitable future of the traditional grid. Since consumers are the key component of SGs, providing security and privacy to their personal data is a critical problem. In this paper, a security protocol, namely TPS3, is based on Temporal Perturbation and Shamir’s Secret Sharing (SSS) schemes that are proposed to ensure the privacy of SG consumer’s data. Temporal perturbation is employed to provide temporal privacy, while the SSS scheme is used to ensure data confidentiality. Temporal perturbation adds random delays to the data collected by smart meters, whereas the SSS scheme fragments these data before transmitting them to the data collection server. Joint employment of both schemes makes it hard for attackers to obtain consumer data collected in the SG. The proposed protocol TPS3 is evaluated in terms of privacy, reliability, and communication cost using two different SG topologies. The performance evaluation results clearly show that the TPS3 protocol ensures the privacy and reliability of consumer data in SGs. The results also show that the tradeoff between the communication cost and security of TPS3 is negligible.     

Accelerated collection of sensor data by mobility-enabled topology ranks

We study the problem of fast and energy-efficient data collection of sensory data using a mobile sink, in wireless sensor networks in which both the sensors and the sink move. Motivated by relevant applications, we focus on dynamic sensory mobility and heterogeneous sensor placement. Our approach basically suggests to exploit the sensor motion to adaptively propagate information based on local conditions (such as high placement concentrations), so that the sink gradually “learns” the network and accordingly optimizes its motion. Compared to relevant solutions in the state of the art (such as the blind random walk, biased walks, and even optimized deterministic sink mobility), our method significantly reduces latency (the improvement ranges from 40% for uniform placements, to 800% for heterogeneous ones), while also improving the success rate and keeping the energy dissipation at very satisfactory levels.     

一种链式分簇的无线传感器网络路由协议

提出了一种高效节能的链式分簇路由（CCR）协议。CCR协议提出了一种新的高效的双向的链式数据聚合与传输方式,在全网分簇的基础上在簇内使用此传输方式。簇头间通过路由树将采集到的数据发送到指定的唯一与基站通信的根簇头节点。仿真实验证明：CCR协议与LEACH和PEGASIS 2种早期的路由协议相比,其网络寿命分别提高了400％和200％。     

基于低功耗浮标的海洋数据传感采集系统

针对浮标技术在海洋环境监测中的应用,研究并改进了现有的浮标系统,设计并实现了自升降式浮标控制系统,以获取水下不同深度的环境数据,具有很好的安全性和隐蔽性。系统以MSP430处理器为核心,以Si4432为无线收发模块,结合温湿度、光照、加速度、倾角、CTD、溶解氧传感器和SD卡,实现了对海洋数据的采集、存储和传输。经测试,能可靠地将数据传输至岸基模块,满足了设计要求。     

便携式智能油井数据采集装置

介绍一种基于单片机的油井数据测试系统,它可灵活方便地实现数据采集、存储等。阐述了该装置的功能、硬件结构及软件设计。实验结果表明:该装置抗干扰能力强、性能稳定可靠。     

一种基于数字水印的无线传感器网络敏感数据通信协议

基于信息隐藏技术开发了一种用于无线传感器网络的隐蔽的敏感数据通信协议.通过牺牲大值传感数据的精度来隐蔽地传输敏感数据,可广泛应用于多个领域.     

S1240交换机的实时采集和人工备份的计费实现流程

定义一个合适的实时采集和人工备份的实现流程是电信企业在长途电话集中计费所面临的一个重要课题.文章介绍了S1240交换机通过FTAM/CMISE协议方式实现计费数据实时采集的工作原理,并对几种实时采集和人工备份的计费实现流程进行了比较,提出了对先采集再进行数据备份方案的优化和计费流程的定义.