DSP在GSM测试系统中的应用

基于WINDOWS2000平台,结合DSP技术、单片机技术和多模块结构而研制的一种移动电话无线电测试仪能用于GSM900/GSM1800等移动电话的测试。     

大哥大的新潮流——双频手机

我国移动通信业正在迅猛发展,至1998年年底我国移动电话用户总数已突破2400万户,跃居世界第二。随着移动电话入网费的下调,移动电话的用户数更进一步增长,这就造成了工作于单一900MHz频段的GSM900网络的容量接近饱和,导致系统堵塞和漏话问题时有发生。为了解决容量受限问题,就有必要开发新的通信频段,因此工作于1800MHz频段的(GSM1800)网络系统应运而生,电信营运部门把GSM1800网与现有的GSM900网迭加,构成GSM900/GSM1800双频网络。双频网络的最大优点是能够在GSM     

紧密集成的WISMO Pac双频GSM／GPRS模块

采用了专门的Chip-Pac技术,为个人数字助理(PDA)和移动电话手机提供了全套GSM/GPRS解决方案,将高度集成与众多功能合成一体。     

凤凰落梧桐——1994年进入中国的先进通讯技术与产品

中国通讯市场的超凡魅力和厚实潜力吸引了众多的国外厂商,近年来,一些先进的通讯技术与产品纷纷在中国落户: 1.GSM 全球数字移动电话系统(GSM)是当今世界电信业的尖端技术,它使话音信号首次以数字形式传送,与现有的模拟式移动电话系统相比,GSM具有一系     

国外移动电话简介

1．英国英国自1985年开始提供蜂窝移动电话业务。Vodafone公司和Cellnet公司经营900MHz的模拟网和GSM网,Merury的One20ne和Hutchison的Or－ange采用以GSM技术为基础的DCS1800个人通信网（PCN）技术。各个网的运营商为争取用户,竞争非常激烈,不惜血本在手机价格、资费政策等方面大做文章,导致英国的移动电话资费在欧洲处于较低水平。2．芬兰目前芬兰全国移动电话已经超过150万部,平均每3．5人就拥有一部移动电话,是世界上移动电话普及率最高的地区之一。其用户可以在模拟的NMT450或NMT900网和数字GSM900网之间进行选择。芬…     

九大竞争力之三全业务铸就中国联通综合竞争力

中国联通同时经营着GSM和CDMA两张移动通信牌照,还有覆盖全国的、采用ATM/IP技术的统一承载网络,是全球拥有业务最多的电信运营商。因此,中国联通在业务发展方面有极大的竞争优势。在业务创新上,中国联通一直以来不断努力,经营的电信业务由成立之初的移动电话(GSM)和无线寻呼发展到目前的移动电话(包括GSM和CDMA)、长途电话、本地电话、数据通信(包括因特网业务和IP电话)、电信增值业务、无线寻呼以及与主营业务有关的其他业务。     

新品展馆

GAIT软件测试套装产品AC1080 IFR公司推出了可测试下一代GSM/TDMA双模移动电话的GAIT软件测试套装产品AC1080。在PCWindows环境中，AC1080与该公司产品蜂窝系统分析仪（CSA）1900-5和2935GSM测试头一起，可对双模GSM/TDMAGAIT移动电话进行测试。专为测试网络重选过程及GSM主理电信业务（GHOST）所设计的这款产品可模拟GSM和TDMA基站。AC1080中还使用了一些特殊配置，使用户既可发送GSM短消息，又可发送GHOST短消息。MMS内容测试程序包WirelessEntertainmentServices（WES）公司研制出有助于移动运营商采…     

基于GPIB总线的GSM移动电话发射功率自动校准系统

全球移动通信系统协议规定,移动电话的发射功率是可以被基站控制的。为了使系统内的所有终端的功率控制达到一致,就必须对每台移动电话按照GSM规范的要求进行功率校准。介绍了GSM移动电话发射功率自动校准的基本原理,给出了GPIB总线下一套GSM移动电话发射功率自动校准系统的实现方案。在GSM规范的指导下,提出了一种补偿数组的自校准方法,分别对GSM900和DCS1800频率段的每一功率等级的发射功率进行了精确而快速的校准。     

新日本无线推出SP6T天线开关模块与单H桥式驱动器

新日本无线已开发适于用4频段移动电话(GSM900/GSM1800/ CDMA800/CDMA1900)的天线开关模块。NJG1634LK5由SP6T开关和控制用逻辑电路、2个信号发送用低通滤波器(GSM900和GSM1800频段各一个)构成。以3比特控制信号使GSM900/GSM1800/CDMA800/CDMA1900的发送接收等6种模式的切换成为可能。NJG1634LK5实现了拥有高     

提供高速数据传输服务 EDGE助力3G时代来临

EDGE(Enhanced Data Rates for GSM Evolution)技术在北美、欧洲和亚洲正快速普及,这些地区都用它来取代现有的GSM/GPRS网络.目前包括照相手机、短信以及在线音频和视频在内,许多应用都需要通过移动电话网络传送数据,EDGE在理论上能提供三倍于GPRS的峰值数据速率.     

"Ring-Ring" Might Soon Mean Ka-Ching

Readers of the technology industry tea leaves could reach one of two conclusions regarding widespread deployment of a global pay-by-mobile-phone infrastructure: either it so close it will be ubiquitous within three or four years or it so overhyped by mobile carriers that it could be a decade away. The GSM Association, the industry umbrella organization of GSM mobile network operators, announced two major initiatives in which mobile phones would serve as transaction devices. One is a mobile money transfer plan that would enable migrant workers to wire money back home to their families more quickly and easily than existing methods. The other is a worldwide "pay-buy mobile" initiative that would enable payment by mobile phones equipped with chips similar to those on smart cards     

A Testbed for Energy Profile Characterization of IP Services in Smartphones over Live Networks

Mobile phones are becoming pervasively used to access Internet and multimedia contents due to their increasing processing power and its wide range of featured wireless communication technologies (Infrared, Bluetooth, NFC, GSM, UMTS, HSPA, WiMax, LTE). In this paper we also introduce mobile devices as a pervasive testbed platform to characterize the energy consumption profile of Internet services. The most innovative advantage provided by our solution is the testbed’s flexibility and simplicity, making it possible to carry out extensive testing campaigns using actual mobile devices in live networks with real services.     

Mobile IPv6 — Wegweiser in eine mobile Zukunft

Since mobile computing is getting more and more common, wireless technology is increasingly being used for Internet access and other IP-based communications. Some years ago, only a few people were using mobile phones to make telephone calls over GSM, whereas today you will hardly find anyone without his mobile companion in his pocket. In the future people will demand to get connected to the Internet by their IP-enabled smart-phones and PDAs always and anywhere. This article presents the upcoming Mobile IPv6 protocol, which will be the base for tomorrow’s worldwide IP-mobility. Mobile IPv6 will be widespread with the introduction of the Next-Generation Internet (IPv6).     

基于GSM/TD-SCDMA/TD-LTE/WLAN的数据业务互切换技术的研究

研究如何在GSM/TD-SCDMA/TD-LTE/WLAN异构移动通信网络中使用数据业务,保证对各种用户在不同场景下提供相应数据业务的同时,最大化利用网络资源,并提高相应的收益率。通过在智能手机安装网络判决器软件,建立关于GSM/TD-SCDMA/TD-LTE/WLAN的用户行为模型和用户使用策略,根据该策略,指导手机用户终端进行网络判决,选择最优网络进行连接。通过本课题的研究,可以在数据业务方面,实现业务分流,从传统的GSM网络分流到TD-SCDMA网络,WLAN网络和TD-LTE网络中,以实现流量最大化。     

Short message gets longer [GSM]

The short message service (SMS) is one of GSM's best kept secrets. The basic idea is straightforward: by 'stealing' slots in the GSM signalling channel the SMS allows mobile phones, together with PCs and laptops connected to GSM phones, to exchange text messages of up to 160 characters. One of the constraints on the wider use of the SMS is the limit of 160 characters on the length of the message. Vodafone announced a valuable enhancement of the SMS service when the company released details of ETSI (European Telecommunications Standardisation Institute) acceptance of a Vodafone-developed SMS compression algorithm, capable of increasing the SMS message length by around 50%. The new compression algorithm could boost the international acceptance of GSM     

iGSM: VoIP service for mobile networks

This article proposes iGSM: a voice-over-IP value-added service for the mobile network. The iGSM service provides user mobility to subscribers, which allows them to use either GSM handsets or H.323 terminals (IP phones or PCs) to access telecommunications services. We describe how the iGSM registration, deregistration, and call delivery procedures can be implemented without modifying the GSM network. We study how the tromboning effect in the standard GSM system can be avoided when accessing the IP network. Then we investigate the misrouting problem caused by user mobility     

Measurement of EMI on network cables due to multiple GSM phones

As the density of transmitters from mobile telecommunication systems continues to increase there is a greater risk of electromagnetic compatibility (EMC) problems due to the ensemble electromagnetic field from multiple mobile handsets. An analysis of the characteristics of the threat field from multiple handsets is presented allowing prediction of the statistics of the ensemble field. A measurement system designed to detect electromagnetic interference (EMI) from ensembles of cellular phones has been used to quantify the level of EMI on Ethernet cables from multiple global system for mobile communications (GSM) mobiles. The measurements are consistent with a simple statistical model of ensemble signals from GSM sources and electromagnetic modeling of the system     

不断进取的诺基亚

诺基亚公司是一个国际性电信集团，由三个业务公司组成，它主要制造固定网和移动网系统，移动电话及其它通用通信产品，诺基亚在中国北京及上海设有代表处，并有５个合资企业，近几年来，它在中国电信市场上非常活跃，主要提供ＧＳＭ、交换和光纤传输设备。     

基于FPGA和ZigBee技术的智能家居系统

主要设计了一种智能装置——智能家居系统,提出了一种采用FPGA技术与ZigBee的无线技术来完成对智能家居系统的设计.该系统全部采用无线通信技术来完成,省去了重新布线的问题,能够实时采集温度、湿度和光照度信号,通过对信号的处理,使PDA、计算机或手机可以通过Internet或GSM手机网络.在家中无人的情况下,帮助主人实现远程家务:远程烧水,加热洗澡水,开头空调、窗帘等,从而为用户提供一种智能、灵活、方便的生活空间,并大大增强了系统的可扩展性,同样也实现了现代社会“以人为本”的全新家居生活体验.