DVB数字广播台标/字幕插入机

介绍一种用于DVB数字广播的台标／字幕插入机。对系统结构和功能做出了描述,给出了具体的实现,并对未来可进行的拓展工作进行了展望。此服务器可广泛应用于城镇电视台的节目实时插入字幕台标及其他多种数据业务,在经过QAM调制器后可通过DVB标准的广播网直接播送给最终用户,也可以通过IP网广播节目。     

Performance of GSM networks with general packet radio services

Recently, most of the mobile network providers start to introduce general packet radio service (GPRS) in their existing GSM networks. GPRS is the technology that will enable more efficient Internet applications to run on mobile networks even before the installation of 3G systems. However, it is not yet clearly understood, how the new data services will affect the overall network performance. This paper provides a framework for analytical performance evaluation of a single GSM/GPRS cell based on a multidimensional Markov chain model. Important performance measures like new call and handover blocking probabilities, moments of the blocking period distributions, achievable average data rates and resource utilization are determined. Introducing a new connection admission control (CAC) algorithm, different partitioning strategies between GSM and GPRS resources are investigated. Finally, the influence of typical GPRS applications like Internet browsing on traditional GSM services has been studied.     

4G移动通信技术的研究

在还没有完全享受3G移动通信系统商所带来服务的同时,4G移动通信技术的研究已经在逐步的进行着。该文简要分析了:(1)4G的网络结构;(2)4G的关键技术,如OFDM,软件无线电,智能天线技术,MIMO技术。(3)比较了3G和4G不同指标,分析了3G和4G采用的不同技术。(4)初步探讨了4G的现状和发展。     

RFID编码解析网络监控系统的研制

阐述了射频识别(radio frequency identification,RFlD)公共服务中的核心技术--RFID编码解析技术的概念,报告了该领域相关网络监控应用的现状,分析了在RFID编码解析网络中加入网络监控功能的必要性.在研究其网络特点的基础上,结合系统的实际需求选用了SNMP技术,对管理信息数据进行了详细地设计,开发实现了一种RFID编码解析网络监控系统.测试结果表明,该系统不但可以有效监控网络中各服务器RFID解析的运行状况,并且提供编码解析网络拓扑维护等功能.     

UMTS: the fusion of fixed and mobile networking

The Universal Mobile Telecommunications System (UMTS) represents the emerging European standard for next generation cellular systems that transmit data as well as voice on a global basis. The UMTS goals involve the integration of evolved versions of today's second generation digital cellular systems, together with new terrestrial and satellite components. They also address a fusion of the mobile and fixed networks with a much greater role for intelligent network services. The integration scenarios take little account of the proliferation of IP based networks, and some system redesign is necessary to correct for this. To build on the strengths of GSM, the core UMTS network will evolve from the existing GSM service. UMTS support for data will probably be based on GPRS developed for GSM. Speeds available will vary from approximately 100 Kbps for a pre UMTS, GSM based system up to 2 Mbps for new UMTS radio access networks. Future mobile broadband systems may extend this up to 155 Mbps in restricted environments. The ETSI timetable for introducing these new systems shows the first equipment going into service in 2002, with full availability of third generation UMTS services by 2005     

无线网络的资源管理

本文研究了无线网络中的资源管理问题。在下一代无线网络中,无线资源管理对于实现真正的高速无线多媒体业务具有非常重要的意义。随着无线通信的迅速发展和技术的不断进步,人们越来越多地享受到无线通信带来的便捷,然而无线资源(例如,频带、终端的功率等)却日见稀缺。所以需要最优地使用现有的无线资源,以实现最优资源分配。     

无线网络的资源管理

本文研究了无线网络中的资源管理问题。在下一代无线网络中，无线资源管理对于实现真正的高速无线多媒体业务具有非常重要的意义。随着无线通信的迅速发展和技术的不断进步，人们越来越多地享受到无线通信带来的便捷，然而无线资源（例如，频带、终端的功率等）却日见稀缺。所以需要最优地使用现有的无线资源，以实现最优资源分配。     

浅谈广电运营支撑系统的系统管理的设计与实现

从2009年广电大力推广NGBOSS的概念起,到国务院常务会议提出加快三网融合融合,再到三网融合融合写进政府工作报告,广电行业这两年可谓是风起云涌。NGB和三网融合的推出是从根本上改变广电网络运营市场环境体制和业务结构,广电网络运营商将从单一的节目传输运营商转变为综合信息服务提供商,这是实质上的一个转变。我们将新形势下的广电称为新广电,在三网融合时间表已经推出,三网融合试点城市即将推出之际,建设能够为新广电提供运营支撑的下一代综合业务运营支撑系统及新BOSS迫在眉睫。本文首先介绍了运营支撑系统的基本概念,并对运营支撑系统的系统管理功能模块进行设计与实现。     

基于TDOA的空间定位算法

随着第三代(3G)移动通信的发展和美国E911规定的颁布,蜂窝网络移动台(MS)无线定位技术得到了越来越广泛的注视.该服务能够提供有关移动台位置的信息,因此在很多领域有着重要的应用.提出了一种基于到达时间差(TDOA)的三维定位算法.其主要思想是用一新变量代替定位估计中的二次项,把非线性估计转化为两次WLS(加权最小二乘)线性估计.此算法结构简单,计算量较小.通过模拟仿真,结果证明了该算法的有效性.     

基于5G切片和优先级的流量隔离性能研究

随着基于3GPP标准的关键任务(MC)移动宽带技术的部署,可为公共保护和救灾提供宽带通信能力。常见方法是在公共移动网络上提供MC服务和商业流量（CO）,并使用优先级机制来保护拥塞情况下的MC连接。然而,这种方法在特定单元中的MC流量激增前,商业流量不受保护,因为所有资源都将被分配来服务于这种流量。在此背景下,提出了一种稳定性较好的多路MC和具有拥塞保护的商业服务的解决方案,该解决方案是基于5G网络切片特性。本文主要描述了在结合优先级的基础上如何在5G无线电接入网(RAN)中参数化不同的切片以及支持无线电资源分配的底层无线电资源管理(RRM)功能的操作从而为每种类型的服务建立无线电负载保证。通过MATLAB仿真结果表明与仅依赖于优先级化机制的解决方案相比,本次采用的切片配置方法在流量隔离方面得到了改进,为不同类型的服务提供了可靠保障。     

A Modular Approach to Mobile QoS Signaling— Motivation,Design & Implementation

In order to support mobile multimedia applications in next generation wireless IP-based networks, it is necessary to deliver seamless voice, video and data at high quality. Therefore, session mobility and Quality of Service (QoS) for mobile end systems are required. Within this article, the authors point out a new way to approach the problem. Instead of tightly coupling a modified QoS signaling mechanism with a certain mobility mechanism, a more generic and long-term solution is proposed and exemplified on the basis of existing IETF protocols. The connection-less IP network layer is enhanced by a lightweight and truly optional connection-oriented mobile network service, which offers the possibility to establish soft state unicast connections at the network layer. Hence, a connection-oriented network service is available within a radio access network (RAN) architecture to all end systems—mobile or fixed—independent of the application. Thereby, it is possible to integrate QoS and connectivity signaling for mobile end systems, as well as other connection-oriented services like explicit routing or load balancing.     

基于DVB和IP双结构传输模式流媒体视频点播系统的设计与实现

针对互联网流媒体视频点播传输带宽问题,对数字广播协议原理和多协议封装技术做了简单介绍,提出了一种基于IPOVERDVB传输模式互联网-广播网双结构流媒体视频点播系统的设计方案,并给出了一种Web网页视频点播应用具体实现方法;该系统综合了互联网和广播网的网络特性,具有双向交互、稳定可靠,不受用户规模限制等诸多优点。     

Service Adaptability in Multimedia Wireless Networks

Next-generation wireless communication systems aim at supporting wireless multimedia services with different quality-of-service (QoS) and bandwidth requirements. Therefore, effective management of the limited radio resources is important to enhance the network performance. In this paper, we propose a QoS adaptive multimedia service framework for controlling the traffic in multimedia wireless networks (MWN) that enhances the current methods used in cellular environments. The proposed framework is designed to take advantage of the adaptive bandwidth allocation (ABA) algorithm with new calls in order to enhance the system utilization and blocking probability of new calls. The performance of our framework is compared to existing framework in the literature. Simulation results show that our QoS adaptive multimedia service framework outperforms the existing framework in terms of new call blocking probability, handoff call dropping probability, and bandwidth utilization.      

基于GPRS远程自动雨量监测系统

设计了新型通用分组无线业务(GPRS)远程自动雨量监测系统,其借助成熟的GPRS无线数据通信技术,结合Internet构建了基于B/S架构的数据服务中心,通过数据库编程实现雨量站点远程管理和信息查询,开发了雨量信息查询站点,实现在Web上动态显示实时雨量分布图。该系统也为其他数据采集与监测系统提供了一种通用、理想的信息采集处理模型。     

Performance analysis of multi-service wireless network: An approach integrating CAC, scheduling, and buffer management

Traffic management (TM) mechanisms such as Call Admission Control (CAC), Scheduling, and Buffer Management (BM) play a key role in the design of multi-service wireless network by providing service differentiation from diverse applications and assigning the network resources (radio channels or buffer) according to the quality of service (QoS) requirements of each service class. We propose in this work two new models that integrate CAC, Scheduling, and BM in the design of multi-service wireless network. By presenting their Markovian models and their performance metrics, we investigate their respective design tradeoffs and compare their performance.     

基于RFID的食品安全监测追溯系统的设计

采用无线射频识别技术(Radio Frequency Identification,RFID)、无线数据通信技术(GPRS)、网络技术及数据库技术等,构建食品安全监测追溯系统。该系统可以对食品从生产养殖、出场、流通批发到零售环节等进行全过程跟踪、追溯,实现食品的安全监测管理。     

应用射频识别技术的企业网络管理

在企业网络设备和网络信息管理时,使用射频识别技术对传统管理方法进行革新,从需求、功能等方面论述射频识别技术在网络管理的应用,提供了网络管理的新方向。     

基于GPRS的电能表集抄系统设计和应用

简要介绍了GPRS技术,通过中国移动通信有限公司的通用分组无线业务(general packet radio service,GPRS)网络,实现电力系统远程数据采集和传输。本文提出一种基于Sony Ericsson Mobile Communications公司GR47模块和Samsung公司ARM7器件4480的电能远程抄表系统。     

Integer linear programming optimization of joint RRM policies for heterogeneous wireless systems

Wireless systems will be characterized by the coexistence of heterogeneous Radio Access Technologies (RATs) with different, but also complementary, performance and technical characteristics. These heterogeneous wireless networks will provide network operators the possibility to efficiently and coordinately use the heterogeneous radio resources, for which novel Joint Radio Resource Management (JRRM) policies need to be designed. In this context, this work proposes and evaluates a JRRM policy that simultaneously determines for each user an adequate combination of RAT and number of radio resources within such RAT to guarantee the user/service QoS requirements, and efficiently distribute the radio resources considering a user fairness approach aimed at maximizing the system capacity. To this aim, the JRRM algorithm, which takes into account the discrete nature of radio resources, is based on integer linear programming optimization mechanisms.     

Application of satellite navigation system for emergency warning and alerting

One of the key responsibilities of any government is to communicate and disseminate safety information and warnings to the general public in case of an emergency. Traditionally, warnings are issued by the government through a broadcast approach using communication channels such as TV and radio. However this monopolistic approach is now challenged by new technologies and media capable of providing individualised warnings to personal mobile devices. Location-based emergency services and mobile alerts are becoming increasingly prevalent in the provision of emergency warnings. These new modes of emergency services have been adopted by several countries worldwide including Australia. One example is the Australian National Emergency Alert (EA) which is a telephone-based service enhanced with location-based capabilities. This paper introduces the concept of applying global satellite navigation systems such as the Japanese satellite system in the domain of emergency warning and alerting. The Japanese satellite warning system can be tailored to transmit real-time location-based emergency warnings to people's mobile devices while not being constrained by the limitations of ground-based communication technologies. A key advantage of satellite based communication is its high resilience to communication network overload and failure of ground systems and network infrastructure during a disaster. This enables people to obtain necessary information anywhere (outdoor) and anytime during times of disaster. A satellite-based warning system could also be integrated with existing warning services and be used as a complementary technology. This paper examines opportunities and challenges for using satellite navigation systems to deliver warnings and safety messages during emergencies and disasters.