无中心选址对讲机的特点与前景

论述了移动通信组网不一定要有中心,对有中心组网与无中心组网作了对比,介绍了无中心组网设备的关键技术、无中心选址对讲机的特点与前景.     

无中心控制多信道选址通信体制的分析

本文论述了移动通信组网不一定要有中心,对有中心组网与无中心组网作了对比,介绍了无中心组网设备的类型;并对多信道共用技术、数字选呼技术作了阐述。最后总结出无中心组网的三大优点,对其体制在我国的发展前景作了可喜的分析。     

900MHZ无中心网的话务和干扰分析

900MHz无中心多信道选址通信系统的容量究竟有多大,对我国的蜂房公众网有无干扰?本系统内三阶互调干扰是否严重,会不会造成对控制信道阻塞?为了回答人们的疑问,本文对无中心组网的话务量、用户数与服务质量作了计算,并对三阶互调对蜂房公众网和本无中心网的干扰条件和概率作了分析,结论是该系统能够承担中等容量任务,对公众网不会造成干扰,只要从技术上和管理上采取措施,也不会对本网造成有害影响。这些理论分析也被计算机模拟和国内外组网实践所证实。     

卫星通信系统主备网控中心设计

在基于资源按需分配策略的卫星通信系统中,网控中心负责系统的管理控制和运行维护。提出了一种基于自协商策略的网控中心热备份方案,结合链路检测、信令交互和数据同步实现了主备网控中心的自动无缝切换及主备网控中心间网控数据的一致。网控中心主备角色切换不影响当前系统内各地球站的入退网状态、业务通信,有效地保证了通信系统的稳定运行。     

山西省GSM语音信箱与短消息中心建设方案

介绍了ＧＳＭ网语音信箱与短消息中心的基本业务 与功能，讨论了语音信箱与短消息中心组网方 式，提供了山西省的建设方案。     

可变基频激光通信数据传输系统研究与实现

针对无线光通信特点,提出一种基于基带跳频的激光数字通信方法,分析单基频调制与可变基频调制原理,研究激光跳频通信信号帧结构与ASK编解码方法,探讨利用FPGA进行跳频通信及控制的技术实现,并进行 FPGA系统仿真和可变基频激光调制与传输实验。结果表明,采用可变基频的ASK调制编码通信能保证信息传输的安全性,在视距范围内实现了通信控制与字符数据传输,为大气激光通信应用提供一种新的技术途径。     

C~3I通信系统网控中心技术设计研究

针对C~3I通信系统军用数据通信对网控中心的特殊要求,文章重点对构成网控中心所需硬件平台、软件平台、应用软件模块组织等重要技术设计实现进行了研究。本文可对C~3I通信系统总体设计提供参考。     

应急通信保障中无线自组网技术的应用研究

无线自组网具有无中心、自配置和快速组网等显著特点,非常适合用于应急通信保障。首先,介绍了当前国内应急通信的现状和存在的问题。然后,概述了以Ad Hoc网络、无线传感网和无线mesh网络为代表的无线自组网的显著特点和技术优势,并举例说明了无线自组网在应急通信保障中的几种具体应用。最后,展望了应急通信网络今后的发展方向。     

国人通信 立足科技创新求发展

国人通信是中国领先的射频技术开发商,拥有深圳研发基地、泉州研发基地和南京研发基地等3个研发基地,以及射频技术中心、系统技术中心、射频产品中心和网优产品中心等4个技术及产品中心。国人通信多年来坚持走自主创新之路,积极进行新产品和新技术的开发工作,取得了突出成绩。     

车载自组网中的网络与信息安全

因自组织网络无中心的特点,传统有中心网络中成熟的安全保障机制无法得到直接应用。为了使车载通信技术得到更加广泛的应用,安全问题必须得到很好的解决。文章对车载自组网的安全需求及目标进行分析,然后从安全路由、密钥管理和入侵检测3个方面对车载自组网安全研究的现状进行介绍。在这3个方面中,安全路由研究最为广泛,而密钥管理则是保障车载自组网安全的关键。     

无线自组织网络对抗初探

无线自组织(Ad Hoc)网络凭借着组网灵活、无中心、自组织和自由移动的特点,在各种领域得到广泛的应用。从分析研究无线自组织通信网络的组网特点和网络特性入手,研究对无线自组织网络通信信号的截获、信号特征分析、协议特征提取及解析的方法,分析了几种无线自组织网络攻击技术的途径,给出利用无线信道对抗无线自组织通信网络的实现方案设想。     

网络编码在MANET最小能量多播中的应用研究

网络编码理论是当代信息论的重要组成部分,移动特设网络(MANET)是由-组带有无线收发装置的移动终端组成的一个多跳临时性自治系统,利用网络编码理论解决MANET中最小能量多播问题是无线通信中新的研究热点之一.文中阐述了网络编码基本理论在无线通信中应用的技术原理,然后通过构建无线网络节点分层模型分析了基于网络编码的MANET最小能量求解过程,为解决该类型网络中能耗问题提供新的视角.     

基于CPK和能量的安全路由算法

无线传感网是由大量传感器节点组成的网络,具有无线通信、自组织、无中心的组网特性。针对无线传感器网络面临的众多安全问题,从组合公钥和节点能量入手,对LEACH进行改进,提出了一种基于CPK和能量的安全有效路由算法。通过仿真实验,改进的路由协议比LEACH具有更长的寿命,而且在安全性方面也进一步加强了。     

Wireless passive sensor networks - [Accepted from open call]

The primary challenge in wireless sensor network deployment is the limited network lifetime due to finite-capacity batteries. Hence, the vast majority of research efforts thus far have focused on the development of energy-efficient communication and computing mechanisms for WSNs. In this article a fundamentally different approach and hence completely new WSN paradigm, the wireless passive sensor network, is introduced. The objective of the WPSN is to eliminate the limitation on system lifetime of the WSN. In a WPSN power is externally supplied to the sensor network node via an external RF source. Modulated backscattering is discussed as an alternative communication scheme for WPSNs. The feasibility is investigated along with the open research challenges for reliable communication and networking in WPSNs.     

基于ZigBee无线技术的智能家居系统设计

论述了基于ZigBee无线通讯的智能家居控制系统设计,以Android手机为控制中心,ZigBee无线通讯为桥梁,实现一种星型的ZigBee网络在智能家居中的应用。该系统以TI公司的CC2530单片机为主控,通过ZigBee自组网,终端设备将采集到的数据通过Z-stack协议栈,发送到ZigBee协调器,通过串口将数据发送到电脑及手机上并显示出来,实现了对设备的集中管理与控制。测试结果表明,ZigBee组网成功,终端节点能轻易地检测到各子模块连接的传感器信号,并可通过手机控制节点信号。     

Throughput-range tradeoff of wireless mesh backhaul networks

Wireless backhaul communication is expected to play a significant role in providing the necessary backhaul resources for future high-rate wireless networks. Mesh networking, in which information is routed from source to destination over multiple wireless links, has potential advantages over traditional single-hop networking, especially for backhaul communication. We develop a linear programming framework for determining optimum routing and scheduling of flows that maximizes throughput in a wireless mesh network and accounts for the effect of interference and variable-rate transmission. We then apply this framework to examine the throughput and range capabilities for providing wireless backhaul to a hexagonal grid of base stations, for both single-hop and multihop transmissions for various network scenarios. We then discuss the application of mesh networking for load balancing of wired backhaul traffic under unequal access traffic conditions. Numerical results show a significant benefit for mesh networking under unbalanced loading.     

无线Mesh网网络层和MAC层相关研究

随着无线网络技术的发展,无线mesh网凭借其多跳通信能力为拓宽WiFi网络的覆盖率提供了有效的途径。利用低发射功率来提高覆盖率和容量的能力,使其在普遍存在的宽带接入中扮演重要角色。凭借其独特的优势,WMN发展非常迅速,并广泛应用于众多领域。为了更好的说明WMN领域存在的挑战,详细描述了无线mesh网的MAC层和网络层研究状况,并且提出了可能提高多跳网络吞吐量的新协议。     

沙漠多节点宽带通信网络架构与关键技术

针对沙漠区域特殊环境下的资源能源受限的问题,提出了沙漠多节点宽带通信网络架构的构想,并梳理了其关键技术及解决途径。该网络采用两套体制和三层网络的架构,既可以满足低延迟的可靠性传输,又能达到宽带传输的目的。通过不同的通信体制和网络层级响应不同业务的传输,实现了沙漠特殊的无线传播环境和基础设施缺乏的条件下多节点宽带通信组网的目标,以解决沙漠区域信号盲区的通信问题。相应的通信组网技术可扩展应用到未来深空探测行星表面组网。     

The challenges of building mobile underwater wireless networks for aquatic applications

The large-scale mobile underwater wireless sensor network (UWSN) is a novel networking paradigm to explore aqueous environments. However, the characteristics of mobile UWSNs, such as low communication bandwidth, large propagation delay, floating node mobility, and high error probability, are significantly different from ground-based wireless sensor networks. The novel networking paradigm poses interdisciplinary challenges that will require new technological solutions. In particular, in this article we adopt a top-down approach to explore the research challenges in mobile UWSN design. Along the layered protocol stack, we proceed roughly from the top application layer to the bottom physical layer. At each layer, a set of new design intricacies is studied. The conclusion is that building scalable mobile UWSNs is a challenge that must be answered by interdisciplinary efforts of acoustic communications, signal processing, and mobile acoustic network protocol design.     

Cross-Layer Design for QoS Support in Multihop Wireless Networks

Due to such features as low cost, ease of deployment, increased coverage, and enhanced capacity, multihop wireless networks such as ad hoc networks, mesh networks, and sensor networks that form the network in a self-organized manner without relying on fixed infrastructure is touted as the new frontier of wireless networking. Providing efficient quality of service (QoS) support is essential for such networks, as they need to deliver real-time services like video, audio, and voice over IP besides the traditional data service. Various solutions have been proposed to provide soft QoS over multihop wireless networks from different layers in the network protocol stack. However, the layered concept was primarily created for wired networks, and multihop wireless networks oppose strict layered design because of their dynamic nature, infrastructureless architecture, and time-varying unstable links and topology. The concept of cross-layer design is based on architecture where different layers can exchange information in order to improve the overall network performance. Promising results achieved by cross-layer optimizations initiated significant research activity in this area. This paper aims to review the present study on the cross-layer paradigm for QoS support in multihop wireless networks. Several examples of evolutionary and revolutionary cross-layer approaches are presented in detail. Realizing the new trends for wireless networking, such as cooperative communication and networking, opportunistic transmission, real system performance evaluation, etc., several open issues related to cross-layer design for QoS support over multihop wireless networks are also discussed in the paper.