把脉"十二五"应急通信工作

征战"十一五"冲破难关奋力行 "十一五"期间,江苏应急通信工作在体制、预案、指挥手段、装备、队伍建设等方面取得了长足进步,应急能力有了较大提高. 其一,理体制,抓预案.根据<江苏省通信保障应急预案>,设立了应急通信保障领导组,负责领导、组织和协调全省的应急通信保障和通信恢复工作.按照自然灾害、反恐维稳等不同特点和要求,修订了通信网络安全、互联网安全、反恐通信保障、上海世博会通信保障等应急预案;各电信运营企业也制定了各自详实周密的应急通信预案,基本建成了横向到边、纵向到底的应急预案体系.     

无线Mesh组网技术在电力应急语音通信中的应用

为了在应急通信任务发生时仍能快速建立可靠的通信,将无线Mesh网络技术和数字语音通信技术结合起来设计了电力应急保障场所语音通信装备.整个装备选择无线语音对讲设备作为通信终端,一体化便携车载设备作为调度台,实现了群体呼叫、单点对话、短信邮箱、基站漫游等多种调度通信功能.在现场模拟电力应急保障场所,并对无线语音通信装备通信状态进行了实际测试.测试和分析表明所开发的无线语音通信装备的通信质量良好,实现了应急语音通信的主要需求.     

应用无线系统发展山区通信

山区通信是农村通信的一个重要组成部分.由于山区地形复杂,加之经济、文化不发达,给解决通信问题增加了难度.达县地区通、南、巴等县山区长期以来通信是个老大难问题.为了摸索经验有效地解决南江县桃园、槐树、玉泉等边远乡镇不通电话的问题,地区局首先从调查研究入手,抽调了地区局总工室和南江县局的同志组成调查组,深入南江县桃园、槐树、玉泉等山区乡镇考察研究.通过考察和实地试验,使我们对解决山区通信问题的紧迫感有了更深的认识,同时对解决山区通信的途径也得到了一些启示.在此笔者谈谈这次考察研究山区通信的具体情况.     

浅析无线电安全保障中应急通信指挥系统的设计

本文简述了无线电安全保障工作的重要性和建设应急通信指挥系统的必要性.提出应急通信指挥系统设计思路.并描述了应急通信指挥平台架构.软件设计、应急通信系统选择及应用部署等核心技术策略。     

从汶川地震通信问题谈平流层应急通信的应用

汶川地震暴露了我国应急通信系统不能满足突发事件通信需求,必须研究新型应急通信技术以克服当前应急通信存在的问题.提出了一种应用平流层通信技术实现应急通信系统的方法:在由飞艇组成的高空航空平台上装载基于微波技术的应急指挥通信系统和蜂窝移动基站,应急指挥通信系统用于突发事件的指挥通信,蜂窝移动通信用于公众通信.分析表明,平流层应急通信系统符合应急通信需求,具有部署快、成本低、容量大等特点.     

基于多模式的流域通信网络系统建设探讨

本文介绍了流域信息化建设中应用的多种通信模式,并基于GPRS、4G、无线网桥、MSTP专网、VPN等通信模式对流域通信网络建设等进行了深入探讨.     

基于短波的应急通信系统设计

短波通信具有抗毁能力强、设备简单、通信距离远、应用灵活、运行成本低等特点,可用于应急系统通信.介绍了短波通信特点及其网络架构、系统组成以及组网形式,对短波通信所具有的优势进行了分析,并结合应急领域通信可靠、快速有效的要求和特点,强调了短波通信系统作为主要无线接入手段在应急通信中的应用,给出了基于应急通信指挥车的短波应急通信系统的设计方案.     

量子安全通信探讨

从理论研究、实验进展和技术开发的角度简述了量子安全通信的发展历程;阐述了量子通信的过程.简单介绍了相关的量子安全通信技术:量子密钥、量子认证、量子签名、量子加密算法和量子秘密共享等.分析了阻碍量子安全通信实用化的几个因素,最后对量子安全通信的发展作了展望.     

激光通信技术的现状及未来发展趋势

激光通信技术已经成为了通信领域的重要技术,其应用和发展受到了广泛的关注.激光通信技术主要是指利用激光在大气信道中进行点对点的数据传输.这种点对点包括单点对单点,单点对多点、多点对多点等几种形式,传输的数据主要包括语音数据、数字数据、图像数据等.激光通信是一种双向的通信技术,应用了该技术之后,通信传输的效率和质量将得到较大程度的提高,因此,我们有必要对激光通信技术的现状及发展趋势进行深入的研究.     

4G无线通信技术在地铁通信网络中的应用分析

随着无线通信技术的快速发展,人们已经进入了4G移动通信时代,在工业生产、民用生活等领域得到了广泛的普及.地铁通信网络承载了地铁乘客数据传输等功能,引入4G无线通信技术可以提高数据接入、发送、接收等速度,进一步改善乘客信息化体验性能.本文详细地分析了4G无线通信技术发展现状及在地铁通信中引入的必要性,同时分析了其在地铁通信中的覆盖方式,提高地铁通信建设能力.     

基于软件无线电的数字语音岩层通信机

本文论述了一种基于软件无线电的甚低频低码率语音数字岩层通信机 ,它采用了QPSK调制和 FEC信道编码技术。计算机仿真和 DSP编程结果表明 ,与同一硬件平台上实现的数字化单边带岩层通信机相比 ,在带宽相近的条件下 ,语音数字岩层通信机的功放效率高、语音音质好、传输距离远     

The Effects of Three Types of Profane Language in Persuasive Messages

The present investigation was concerned with the effect of using profanity in a communication on receiver attitude change and speaker credibility ratings. Results of the investigation found no support for the superiority of a persuasive communication using profanity of a religious, excretory, or sexual nature over the same communication devoid of such profanity. It was found, however, that if one of the above three types of profanity is included in a communication, greater attitude change can be expected to occur if the communicator is a female using any one of the three profanity-types mentioned than if the communicator is a male using the same types of profanity. Finally, it was found that using profanity in a communication generally has a detrimental effect on the perceived credibility of the communicator.     

A coding theorem for a class of unknown channels

We consider the problem of communication over a channel which is selected 1) in a fashion unknown to the communicator, 2) as a function of past history, 3) from a given set of discrete memoryless channels, and 4) for the purpose of maximizing the degradation in performance. An upperbound on error probability insurable with block coding is obtained which exponentially approaches zero with block length for rates less than capacity. Techniques for the communicator to achieve these results are considered. The design of relatively simple communication techniques for channels with memory and jammed channels are discussed.     

分组无线通信控制器的设计

文章介绍了一种新型的用于组成无线计算机通信网的通信控制器的设计,这种通信控制器具有高速的特点,它可以利用一般的ＵＨＦ,ＶＨＦ通信机通信,组成计算机分组无线网。     

通信传输技术九十年代新动向

本文概述九十年代通信技术的新动向,主要讲卫星通信、移动通信、光纤通信以及公用和专用通信网传输技术的发展趋势。文中着重指出各种有前途的新技术,包括卫星通信的星上点波束天线,小孔径天线地面终端,与ISDN兼容;数字移动通信的蜂窝微区(micro-cell),个人便携通信的无线接入交换网;光纤通信的掺铒光纤放大器,DFB调谐单频激光管,多量子阱(MQW),光电子集成,外差检测,密集FDM多路载波通信;以及公用通信网数字化、综合化、宽带化组成B-ISDN,同步光纤网,同步数字体系,异步转移方式;专用通信网的局域网(LAN和MAN),光纤分布数据接口,分隙环(slotted ring),分布排队双总线等新建议。     

存在检测误差的抗跟踪干扰最优跳速设计

跟踪干扰对跳频通信构成严重威胁。首先采用Stackelberg博弈模型对存在检测误差条件下的通信干扰与抗干扰进行建模,在该模型中,存在一个先行者和一个跟随者,其中,通信方作为先行者进行跳频通信,跟踪干扰方作为跟随者检测跳频通信信号并实施干扰。分别推导了通信方的最优跳速,以及干扰方最优检测时间与干扰时间的分配策略,证明了当信噪比小于一定门限时,干扰方的最优干扰策略是盲干扰,通信方的最优抗干扰策略是慢速跳频。最后,对理论分析结果进行了计算机仿真验证,并将所提算法与盲跳频和变速跳频进行了比较,结果表明,所提算法的抗跟踪干扰性能显著优于已有算法。      

Knowledge transfer in virtual systems development teams: an exploratory study of four key enablers

Knowledge transfer among geographically separated members is recognized as a critical ingredient for collaborative accomplishment of work in virtual teams. However, due to the "localness" of knowledge, such transfer of knowledge is believed to be inherently problematic; thus, it is important to develop a solid understanding of the factors that enable knowledge transfer in such contexts. Drawing on existing literature on knowledge management and virtual teamwork, we identify four Cs (communication, capability, credibility, and culture) associated with individuals who transfer significant amounts of knowledge to remote members. Next, we test the four Cs in the context of US-Norwegian virtual teams engaged in systems development. The volume of communication, the credibility of the communicator, and the nature of cultural values held (i.e., collectivism) by the communicator were found to significantly predict the extent of knowledge transferred; although, contrary to expectations, capability was not found to have a significant influence. A number of implications for virtual team participants and professional communicators are articulated. Avenues for future research are also suggested.     

Communication as Adaptation

Each and every act of communication between human beings can be considered as an adaptive process analogous to biological evolution. The act of communication, both verbal and non-verbal, represents our best attempt to adapt to the specific situation. This communication adaptation made in responye to environmental events affects that same environment which in turn affects again the communicator. This paper is concerned with communication as both a process and an outcome. It is based on the assumption that, like evolution, Communication is never complete. Behavioral acts of communication such as words and gestures once emitted cannot be revoked. Typically, we note and respond to this static aspect of communication and ignore equally important process dimensions. A process approach to communication implies recognition that communication acts are at best approximations of the reality of experience which occurs in and between individuals. The major thesis of this gaper is that, just as in evolutionary biology, there is no foreseeable end-point in communication. The propensity to treat communicative acts as ends, omitting the fact they are also processes, may be a major barrier to man's ability to communicate with his fellows.     

Analysis of an on-off jamming situation as a dynamic game

The process of communication jamming can be modeled as a two-person zero-sum noncooperative dynamic game played between a communicator (a transmitter-receiver pair) and a jammer. We consider a one-way time-slotted packet radio communication link in the presence of a jammer, where the data rate is fixed and (1) in each slot, the communicator and jammer choose their respective power levels in a random fashion from a zero and a positive value; (2) both players are subject to temporal energy constraints which account for protection of the communicating and jamming transmitters from overheating. The payoff function is the time average of the mean payoff per slot. The game is solved for certain ranges of the players' transmitter parameters. Structures of steady-state solutions to the game are also investigated. The general behavior of the players' strategies and payoff increment is found to depend on a parameter related to the payoff matrix, which me call the payoff parameter, and the transmitters' parameters. When the payoff parameter is lower than a threshold, the optimal steady-state strategies are mixed and the payoff increment constant over time, whereas when it is greater than the threshold, the strategies are pure, and the payoff increment exhibits oscillatory behavior     

Frequency-hopped spread spectrum in the presence of a followerpartial-band jammer

A countermeasure to a partial-band follower jammer is proposed for frequency-hopped spread-spectrum communications. This technique randomizes the transmission technique used by the transmitter (and receiver). Either the information is carried by M tones which are transmitted in a frequency slot, or by M frequency slots which contain signal energy. As a counter-countermeasures, the jammer randomizes between jamming the same frequency slot being used by the communicator, or jamming a subset of the slots not being used by the communicator. The performance for randomized strategies for the communicator and jammer is investigated. It is shown that the proposed technique enhances the system's performance