铁路通信中光纤接入网技术的应用

随着铁路高速化、信息化、现代化程度越来越高,铁路对通信的要求也越来越高,而光纤能够满足铁路通信系统的高速率、大容量等对信息传送功能的特殊要求,它必将成为铁路通信中接入网的关键技术.本文在简单介绍了光纤接入网技术的实现之后,探讨了这项技术在我国铁路通信中的应用.     

即时通信的商务畅想

1998年,四个以色列年轻人推出现在已为大家熟悉的ICQ互联网通信工具,即时通信(IM)首次出现。经过6年的发展,大多数互联网用户已经离不开QQ、MSN了。即时通信已成为继上网浏览、发布信息、电子邮件、搜索引擎之后的第五大互联网应用服务。而且,随着即时通信技术的完善和市场需求的扩大,即时通信已不再单单扮演一个供人娱乐消遣的角色,它的许多功能已经能够较好地满足商务用户的工作需求。     

基于Android手机摄像头的视频监控平台设计与实现

当前,智能手机已经成为一种普遍的通信工具,随着信息技术以及手机厂商不断的产品迭代,新的高端手机不断地出现.智能手机的更新换代速度越来越快,导致人们更换手机的频率也变高了.视频监控设备目前大多价格昂贵,而且操作复杂.利用淘汰的智能手机的摄像头开发附加功能成为旧手机重复利用的一种趋势.     

校园无线网络的安全分析与防范策略

互联网技术和智能手机技术快速发展,无线网络成为新一代网络组建的趋势,它可以摆脱传统网线的束缚,在无线网络的覆盖范围内便捷快速地访问互联网信息。学生作为智能手机和互联网的热衷者,几乎人手一台智能手机,随着教育信息化的不断发展,学校无线网络建设顺应信息社会的发展,给师生提供更人性化的教学环境,可以随时随地在校园的各个角落上网。     

智能掌上时代

现在智能手机的发展相当迅速，从每一款产品问世到今天短短数年间，不仅智能手机的产品已变得相当成熟，市场销售亦开始得到更广泛的认同，随着硬件的迅速发展，现在的智能手机不仅能够实现手机功能，还能够实现多媒体互动，个人信息管理，互联网信息查询等功能，智能手机已经能够用多种方式来帮助用户管理日常生活。     

此情可待智能手机

越来越多的人开始相信智能手机有发展成为微型电脑的趋势,而且随着智能手机的功能性、应用性逐步提升,它也越来越适应微型电脑这个角色。但是否智能手机最终能够越俎代庖取代笔记本电脑成为我们主要的应用工具呢？我们不妨从智能手机本身以及手机网络等几个层面进行分析和展望。其中的智能手机部分我们不但会介绍国内目前火热的智能手机产品,还会和用户分享国外用户热衷的智能手机。另外,智能手机的应用不分国内和国外,先了解一下国外用户的应用需求,对国内用户具有一定的前瞻意义。     

基于智能手机和RFID的内河航运动态监管与信息服务系统研究

近年来,我国的内河航运得到了长足发展,其运能大、占地少、能耗低、污染小的独特优势和带动经济社会发展的作用逐步凸显。然而,由于航道分布广泛、错综复杂且通行船舶大小各异,我国的内河航运很难实现对船舶的全面动态监管,不能提供优质的信息服务。随着计算机技术和电子技术的不断发展,GPS、AIS、RFID等技术在内河航运监管与服务系统也逐渐出现,此类技术的应用在一定程度上实现了船舶的动态监管或信息服务。针对现有技术因为岸基建设成本或终端成本高而无法实现推广的状况,将充分利用智能手机定位功能和RFID的身份识别功能,同时结合手机通信网络,提出一种基于智能手机和RFID的内河航运管理与服务系统。该系统借助于现有网络运营商的手机通信网络,只需要增加一个RFID标签和在智能手机上安装一个第三方软件便可实现对船舶的全面动态监管,并能提供丰富的信息服务。极大降低了内河航运监管与服务系统的建设成本,具有较强地实际推广意义。     

基于安卓的数字警察助手软件

随着电子信息技术的快速发展,智能手机的使用客户日益增加,它已经成为人们生活不可缺少的一部分,同时也是人们获得信息主要来源之一。而且,手机服务已经涉及到人们的各个方面,手机警察助手软件服务就是其中的一项。由于Android平台具有强大的兼容性,适合各种应用的开发设计,它成为当前使用最广泛的智能手机操作系统,目前android4.0是它的最新版本,使智能手机的操作变得更加灵活。     

基于CORBA的分布式Agent通信构架

随着Internet的不断发展,传统的搜索引擎在信息获取上显露出明显的不足。Agent技术的出现使得个性化的主动信息服务成为可能,但是单个Agent的能力有限,因此需要在Agent之间进行通信与交流,实现社会过滤以提高信息服务的质量,为了解决Agent的运行平台和底层通信机制的异构性问题,提出了基于公用对象请求代理体系结构CORBA的分布式Agent通信构架－－CADA.Agent获取用户的信息需求并用KQML进行描述,它通过通信器与其他Agent进行信息交流,通信器对接收到的服务请求进行过滤,将其转发到能够提供该服务的Agent,最后把处理结果返回给客户端．CADA屏蔽了运行平台和底层通信机制,能够有效地解决分布式Agent的通信问题。     

一种混合的Tor匿名通信系统

提出了一种混合的Tor匿名通信系统方案,它不仅能够保证Tor系统低的通信延迟,而且还能够排除其因未使用填充信息和批量处理技术而导致的安全问题.它确保了Tor匿名通信系统能够更加可靠地运行,实现用户身份隐藏.     

Towards a Semantic Driven Framework for Smart Grid Applications: Model-Driven Development Using CIM, IEC 61850 and IEC 61499

Power and energy systems are on the verge of a profound change where Smart Grid solutions will enhance their efficiency and flexibility. Advanced ICT and control systems are key elements of the Smart Grid to enable efficient integration of a high amount of renewable energy resources which in turn are seen as key elements of the future energy system. The corresponding distribution grids have to become more flexible and adaptable as the current ones in order to cope with the upcoming high share of energy from distributed renewable sources. The complexity of Smart Grids requires to consider and imply many components when a new application is designed. However, a holistic ICT-based approach for modelling, designing and validating Smart Grid developments is missing today. The goal of this paper therefore is to discuss an advanced design approach and the corresponding information model, covering system, application, control and communication aspects of Smart Grids.     

A survey of communication/networking in Smart Grids

Smart Grid is designed to integrate advanced communication/networking technologies into electrical power grids to make them “smarter”. Current situation is that most of the blackouts and voltage sags could be prevented if we have better and faster communication devices and technologies for the electrical grid. In order to make the current electrical power grid a Smart Grid, the design and implementation of a new communication infrastructure for the grid are two important fields of research. However, Smart Grid projects have only been proposed in recent years and only a few proposals for forward-looking requirements and initial research work have been offered in this field. No any systematic reviews of communication/networking in Smart Grids have been conducted yet. Therefore, we conduct a systematic review of communication/networking technologies in Smart Grid in this paper, including communication/networking architecture, different communication technologies that would be employed into this architecture, quality of service (QoS), optimizing utilization of assets, control and management, etc.     

Smart Dust: communicating with a cubic-millimeter computer

The Smart Dust project is probing microfabrication technology's limitations to determine whether an autonomous sensing, computing, and communication system can be packed into a cubic millimeter mote (a small particle or speck) to form the basis of integrated, massively distributed sensor networks. Although we've chosen a somewhat arbitrary size for our sensor systems, exploring microfabrication technology's limitations is our fundamental goal. Because of its discrete size, substantial functionality, connectivity, and anticipated low cost, Smart Dust will facilitate innovative methods of interacting with the environment, providing more information from more places less intrusively     

ZigBee无线通信网络节点设计与组网实现

随着ZigBee技术的迅速发展,ZigBee无线通信网络在智能家居中得到越来越多的应用;简单介绍了ZigBee协议的架构,设计了由MSP430单片机和CC2420射频芯片构成的ZigBee无线通信网络节点,系统地分析了节点硬件结构及加入网络的软件流程,详细阐述了多个节点的网络拓扑方案;通过试验测试表明,该网络节点具有较好的稳定性和较高的通信效率,可以满足智能家居对无线通信网络传输及组网要求。     

PC＋时代搭建智能家居平台的探索与研究

智能家居生活已随着现在的高速网络与现代通信设备的发展,逐渐从原来的幻想成为现实,现代科技带给人们的不仅仅是技术的进步,而是化单一为多样,能够让更多的家庭获得完美的新型家居娱乐体验。基于高速无线网络环境的PC＋智能家居平台构建了全套智能家居的统一共享与应用,随着未来物联网的不断拓展,更多丰富的设备将加入到PC＋环境中,未来人类的智能生活指日可待。     

Cyber security in the Smart Grid: Survey and challenges

The Smart Grid, generally referred to as the next-generation power system, is considered as a revolutionary and evolutionary regime of existing power grids. More importantly, with the integration of advanced computing and communication technologies, the Smart Grid is expected to greatly enhance efficiency and reliability of future power systems with renewable energy resources, as well as distributed intelligence and demand response. Along with the silent features of the Smart Grid, cyber security emerges to be a critical issue because millions of electronic devices are inter-connected via communication networks throughout critical power facilities, which has an immediate impact on reliability of such a widespread infrastructure. In this paper, we present a comprehensive survey of cyber security issues for the Smart Grid. Specifically, we focus on reviewing and discussing security requirements, network vulnerabilities, attack countermeasures, secure communication protocols and architectures in the Smart Grid. We aim to provide a deep understanding of security vulnerabilities and solutions in the Smart Grid and shed light on future research directions for Smart Grid security.     

The AXIOM software layers

People and objects will soon share the same digital network for information exchange in a world named as the age of the cyber-physical systems. The general expectation is that people and systems will interact in real-time. This poses pressure onto systems design to support increasing demands on computational power, while keeping a low power envelop. Additionally, modular scaling and easy programmability are also important to ensure these systems to become widespread. The whole set of expectations impose scientific and technological challenges that need to be properly addressed.The AXIOM project (Agile, eXtensible, fast I/O Module) will research new hardware/software architectures for cyber-physical systems to meet such expectations. The technical approach aims at solving fundamental problems to enable easy programmability of heterogeneous multi-core multi-board systems. AXIOM proposes the use of the task-based OmpSs programming model, leveraging low-level communication interfaces provided by the hardware. Modular scalability will be possible thanks to a fast interconnect embedded into each module. To this aim, an innovative ARM and FPGA-based board will be designed, with enhanced capabilities for interfacing with the physical world. Its effectiveness will be demonstrated with key scenarios such as Smart Video-Surveillance and Smart Living/Home (domotics).     

Smart consumer load balancing: state of the art and an empirical evaluation in the Spanish electricity market

The basis of an efficient functioning of a power grid is an accurate balancing of the electricity demand of all the consumers at any instant with supply. Nowadays, this task involves only the grid operator and retail electricity providers. One of the facets of the Smart Grid vision is that consumers may have a more active role in the problem of balancing demand with supply. With the deployment of intelligent information and communication technologies in domestic environments, homes are becoming smarter and able to play a more active role in the management of energy. We use the term Smart Consumer Load Balancing to refer to algorithms that are run by energy management systems of homes in order to optimise the electricity consumption, to minimise costs and/or meet supply constraints. In this work, we analyse different approaches to Smart Consumer Load Balancing based on (distributed) artificial intelligence. We also put forward a new model of Smart Consumer Load Balancing, where consumers actively participate in the balancing of demand with supply by forming groups that agree on a joint demand profile to be contracted in the market with the mediation of an aggregator. We specify the business model as well as the optimisation model for load balancing, showing the economic benefits for the consumers in a realistic scenario based on the Spanish electricity market.     

Improving the reliability of wireless data communication in Smart Grid NAN

The communication network of a Smart Grid has a three-level hierarchical structure consisting of Home Area Network (HAN), Neighborhood Area Network (NAN) and Wide Area Network (WAN). Wireless communication, due to its advantages, is identified as a potential candidate for Smart Grid communications, especially in HAN and NAN. However, wireless transmission is inherently unreliable, whereas communication reliability is one of the fundamental requirements of Smart Grid applications. In this paper, a two-layer communication model based on IEEE reference grids is considered for NAN and a method based on transmission redundancy is proposed to improve the reliability of wireless communications in NAN, while the communication delay requirement of the Smart Grid is considered as a restriction. The proposed method finds the optimum number of transmissions at each hop with respect to the loss probability and total delay constraints. Comparing the proposed method to the case of an equal number of transmissions for all the hops, it is shown by analysis that the proposed method achieves a superior reliability while meeting the delay requirement. In addition, the simulation-based evaluation of the proposed method supports the validity of the results obtained from the analytical model.     

Network management needs for the wireless communication environment

As the wireless market matures and enters the personal communication era, users will be presented with an exciting array of new, global voice, data, video, and multimedia services. Providers of these services will be hard pressed to utilize new and expensive technologies, and provide high quality service at rates that are economical enough to attract the large customer base that would make these services viable. This implies that many diverse network resources must be optimally utilized and managed. Service providers would need to manage their entire network in an integrated, end-to-end fashion, with minimal technical staffing and expertise. Smart, real time, Network Management (NM), thus, is becoming ever more important for the realization and viability of Personal Communication Services. This paper will examine network management for these emerging services, compared with current wired (i.e., nonwireless) and cellular wireless NM. We will compare NM in both the AMPS and GSM standards, and examine the NM needs of future wireless technologies. We conclude with our view of the directions that NM will take over the next few years.