FAE:一种OpenFlow协议FlowMod消息的action扩展机制

SDN网络对数据转发平面的抽象是OpenFlow等南向接口协议制定的前提,目前标准OpenFlow协议假设数据平面每个流表项由确定的规则定义和对应的动作集合组成,每个配置数据平面的FlowMod消息会携带这些规则和动作集合。然而,随着SDN应用场景的不断发展,OpenFlow协议有限的预定义动作难以满足一些新的配置需求,例如集中控制的段路由管理配置和SDPA的配置等。为了提高当前SDN对动作定义的灵活性,解除其对动作的限制,首先提出了一种基于OpenFlow协议FlowMod消息的action扩展机制FAE,该机制具有满足用户自定义动作,且动作扩展灵活简单的特点,然后基于开源的Floodlight控制器和FAST交换机实现了FAE机制,实验表明,该机制在集中控制的段路由下,可以有效地支持其管理配置中的动作。     

基于ZigBee技术的养老院无线紧急呼叫系统

ZigBee遵循IEEE802.15.4新型无线通信网络协议。文章提出把ZigBee技术应用于养老院的新思路,研究设计了养老院无线紧急呼叫系统.论述了基于C8051F020和CC2430芯片组成的无线网络收发器,介绍了ZigBee技术的特点和CC2430芯片。     

无线传感器网络链路状况对密钥协商的影响

无线传感器网络链路损耗大,密钥协商不能一次成功。为了研究无线传感器网络链路状况对密钥协商的影响,提出一个高区分度的评估指标——加权安全连通率,通过分析影响密钥协商的因素及对多个不同密度的网络进行密钥协商仿真,找出无线传感器网络链路状况对密钥协商的影响规律。仿真结果及分析表明,网络布置保持节点间距在最大通信距离的2/5左右,能使安全连通率较优。     

一种基于WSN的井下无线应急通信节点设计

针对煤矿井下应急通讯应用需求,提出了基于无线传感器网络(WSN)的井下无线应急通信系统架构,设计由微处理器电路、无线收发模块、传感器电路、电源、和天线所组成的井下无线应急通信系统节点,低功耗设计;按照功能开展模块化,提高节点灵活适用性;最后测试了设计节点点对点通信性能,得到相应的距离与丢包率之间的关系曲线;井下无线应急通信有效通信距离达到45 m,能够满足井下大规模应用组网需求.     

基于LoRa无线技术的地震应急救援坍塌信息获取

为准确获取到地震坍塌信息,提高救援抗灾能力,提出了基于LoRa无线技术的地震应急救援坍塌信息获取方法。首先分析LoRa无线技术传输系统工作流程,考虑受灾环境多径效应,在LoRa无线系统中使用三边定位锚点,估算坍塌位置节点,得到与实际位置的距离间隔;其次选用三轴高分辨率加速度传感器作为信息获取模块,以无线振动的形式完成信息采集,建立信息获取性能评估函数,提高获取性能,并对获取到的信息幅值采用相位差值算法较正,对得到的坍塌信号频率及相位完成修正,确保可准确的得到受灾区域相关信息数值;最后通过与支持向量机对比获取到的信息数量与准确率、地震区域坍塌类型、及加入其它地形作为干扰因素进行仿真,仿真结果显示,所提方法具有更高的准确率与稳定性。     

基于无线Mesh网络的煤矿应急救援系统设计研究

针对煤矿井下巷道特点,指出煤矿井下无线Mesh网络适于组建链状网络拓扑结构,并应结合巷道具体环境进行电磁波衰减理论分析和节点间距设计;针对现有的路由协议不能满足煤矿井下无线Mesh网络链状拓扑结构的要求,结合MIC判据,提出了一种反应式路由协议与先验式路由协议相结合的方法;在此基础上,给出了基于无线Mesh网络的煤矿应急救援系统的整体结构及特点。实验结果表明,把无线Mesh网络应用到煤矿应急救援系统中,提高了救灾工作的安全性、可靠性及灵活性。     

Inter-organizational Emergency Medical Services: Case Study of Rural Wireless Deployment and Management

Over the last two decades, use of mobile communications for emergency services (e.g. 911) has grown exponentially. This rise of mobile networks has increased reliance on new private and public partnerships to deliver these time critical services. Drawing upon complex systems theory and Inter-organizational Systems (IOS) dynamics, a framework is developed for investigating technology, organizational and policy dimensions of Emergency Medical Services (EMS). The case study for this investigation is rural Minnesota, where a series of semi-structured interviews were conducted and supplemented by analysis of candidate EMS system evaluations. The twofold objectives of the study were to explore the nature of inter-organizational dynamics in this setting and to set forth an architecture for measuring and enhancing performance. Key technology concerns included gaps in wireless coverage, complex system upgrades, and lagging integration of wireless communications into existing infrastructures. These issues were intertwined with organizational aspects, such as the challenges in developing coordinated relationships among agencies and between the public and private sectors. Several policy levers were also influential, such as federal standards that had been set forth for E-911 location information and funding initiatives in the transportation area. The final section draws upon these findings to suggest an EMS architecture that portrays the entire system as well as critical IOS linkages. While IOS has traditionally examined supply chains, these findings are aimed to contribute to understanding more complex, dynamic and heterogeneous socio-technical processes. The paper concludes with a discussion of management and research implications.     

User behaviour towards protective information technologies: the role of national cultural differences

Computer technologies that protect data and systems from viruses, unauthorized access, disruptions, spyware and other threats have become increasingly important in the globally networked economy and society. Yet little is known about user attitudes and behaviour towards this category of information technologies. Comparative studies across different cultures in this context are even rarer. In this study, we examine the cross-cultural differences between South Korea and the United States in user behaviour towards protective information technologies. We develop a theoretical model of user behaviour based on the framework of the theory of planned behaviour and national cultural dimensions and indices. We posit that cultural factors moderate the strength of the relationships in the behavioural model in the context of protective information technologies. The model was then empirically tested using structural equation modelling techniques in conjunction with multi-group analysis. Most of the hypothesized moderating effects of national cultural factors were found to be statistically significant. Our findings suggest that cultural factors should be considered in order to design effective information security policies, practices and technologies in global networks where multiple cultures coexist. Theoretical and practical implications of the study are discussed.     

施工隧道无线传感监控网络紧急路由协议研究

施工隧道是一种狭长封闭、环境恶劣、且事故多发的空间,对监控网络的可靠性和实时性要求高.根据正常监测和紧急状况下对网络路由协议的不同要求,监控网络存在两种数据传输模式:一是常规通信模式,二是紧急通信模式.针对隧道中无线传感网络的部署特点,提出一种基于定向扩散原理的紧急路由协议,以保证紧急通信模式下路由协议的实时性和可靠性...     

基于无线传输和USB接口的远程诊断与急救支援系统设计

紧急危重病人的前期医疗处理对于挽救病人的生命是十分重要的,为此研制开发了一套基于无线收发和USB接口相结合的远程诊断与急救支援系统。该系统能动态地获取患者的生命指征和静态图像,这些数据经现场的便携计算机处理后通过GSM接入互联网,使现场的医护人员能够及时得到远程会诊中心的专家指导。     

应急通信中基于ANP的WSN可生存性评价指标体系研究

建立科学合理的可生存性评价指标体系,可以有效评价和验证应急通信中无线传感网(WSN)的可生存性,进而采取必要措施增强其生存能力。首先,筛选出应急通信中无线传感网的可生存性评价指标集,并建立基于网络分析法(ANP)的评价模型框架。然后,通过网络分析法(ANP)确定相应指标的权重并构建WSN生存性指标体系。最后,利用该指标体系对采用SRPC协议和RLEACH协议的WSN可生存性进行综合评价。分析和验证结果表明,提出的指标体系能够较为客观有效地评价WSN的可生存性。     

基于无线传感器网络的煤矿报警系统节点的设计及实现

将无线传感器网络技术融入煤矿视频监控系统中,传感器节点由传感模块、处理模块、通信模块和电源模块组成.微处理器选用ATMEL公司的ATMELGAl28L,射频芯片选用NORDIC公司的nRF24L01.采用节点定时打开与关闭的协议且打开与关闭的时间比为1∶99.充分考虑节能和扩展性的需求,系统支持多种目标文件格式.     

基于Mesh技术的矿井应急救灾通信系统设计研究

针对矿井应急通信系统存在的呼吸器影响语音清晰度、缺少视频信息、缺少环境参数监测和传输功能等问题,提出了一种基于无线Mesh技术的矿井应急救灾通信系统设计方案,简要介绍了无线Mesh的基本原理及结构,给出了矿井应急救灾通信系统的组网方式、整体架构和主要设备的设计方案,详细阐述了网络服务质量的保证、无线Mesh网络的动态路由选择、业务准入与控制和音视频流无缝移动传输等关键技术难题及解决办法。实际应用表明,该系统能同时实现井上指挥中心、井下指挥中心和井下救护人员之间的语音和视频通信功能,并能在井上和井下指挥中心实时显示救灾现场的环境参数。     

Guest Editor's Introduction: Wired on Wireless

In the past few years, we’ve seen wireless keyboards, mice, headsets, broadband networking, and even high-fidelity speakers. Radio frequency-based products’ move toward the consumer space has greatly reduced the equipment’s price, and this in turn has caused a groundswell of new consumer- and enterpriseoriented products that use wireless technology. This, however, creates the potential for security and privacy problems--the focus of this special issue. The articles in this issue aim to have frank and open debates on the problems as well as advantages so that the results benefit everyone.     

无线网络编码研究综述

网络编码允许网络上的各个转发节点在转发数据的基础上参与数据处理,是一种提高网络吞吐量和网络可靠性的有效方法。文章在介绍网络编码的基本原理的基础上,概述了无线网络中各种基于网络编码的传输机制,从传输时间、可靠性能等方面评述了各种方法的优缺点,最后对无线网络编码的发展趋势进行了分析和展望。     

The meaning of action: a review on action recognition and mapping

In this paper, we analyze the different approaches taken to date within the computer vision, robotics and artificial intelligence communities for the representation, recognition, synthesis and understanding of action. We deal with action at different levels of complexity and provide the reader with the necessary related literature references. We put the literature references further into context and outline a possible interpretation of action by taking into account the different aspects of action recognition, action synthesis and task-level planning.     

Interacting arguments in crisis communication: The influence of message convergence on risk and crisis messages

By their nature, risks, and crises create uncertainty. This uncertainty causes both discomfort and confusion for those seeking to protect themselves and their loved ones from the threat at hand. As more information is revealed about a risk or crisis, interacting arguments often coalesce to reveal points or convergence. This exploratory study examined the relationships among message convergence and the desire to seek additional information, source credibility, risk severity, and perceptions of message consistency in response to a notable risk to the food supply. Results indicated that those participants viewing content with high convergence had heightened perceptions of source credibility, risk severity, and message consistency. They did not, however, indicate a need to seek further information. These results suggest that organizations and agencies offering warnings about risks and crises can benefit from message convergence.     

无线信道自适应传输技术综述

文章对基于地面无线通信的无线信道自适应传输技术的最新研究进展进行了总结,按发送端ACM自适应传输技术、接收端自适应传输技术进行分类,介绍了发送端的可变速率调制、自适应编码、混合自动重传请求和接收端的无速率码、速率自适应解调等相关技术的基本思想、技术实现及特点,并分析比较了发送端802.11b ACM、接收端速率自适应等典型技术的吞吐量性能。指出了无线信道自适应传输技术的研究趋势,最后介绍了地面无线信道自适应传输技术在卫星通信中的扩展应用,对于无线自适应技术的研究具有参考意义。