固定电话网增值化改造探讨

分析了固定本地电话网存在的问题,并就如何通过增值化改造提升网络的价值及延长设备生命力进行了较深入探讨,对固定电话网今后的发展提出了建设性意见.     

基于VoIP技术视频会议系统研究与设计

为了实现视频会议的IP网络与传统的PSTN网络互通,由于现有的SmartMeeting系统是一个纯粹的IP网络视频会议,这样就不能够利用传统的PSTN网络下的电话进行视频会议,故该系统采用增加VoIP网关进行对H．232协议和SIP协议做了相应的协议装换的分析,在现有SmartMeeting系统的基础上对IP网络与PSTN网络进行互通功能实现进行详细的研究与设计。系统是在VC＋＋6．0平台下开发,采用C／S模式实现的。     

软交换技术的应用与发展

IMS技术的逐渐兴起，对软交换技术的发展产生了新的挑战。与IMS相比软交换更适合于实现传统的窄带话音业务，因此软交换后续的发展应该定位于在分组交换网络上继承和发展传统语音业务。在这一定位的基础上，软交换可以应用于公共交换电话网（PSTN）长途网以及网络智能化改造当中，同时软交换的一般网络架构也会随着业务的发展和提高服务质量的需求而有所变化。     

软交换中基于VoIP语音识别的业务部署方案

本文提出了一套基于VoIP语音捕获及其识别的业务部署方案,该方案可以在不改变现有通信网络结构和业务部署的情况下,利用语音识别技术,继承或扩展非IP网的通信业务,也可以在IP网中部署新的增值业务。实验环境下的验证结果表明,该方案具备实际部署的可行性。     

浅谈固网智能化及其相关问题

文章通过对固网现状的分析,结合固网业务属性数据寄存器(SHLR)技术,提出了当前固网智能化的几种实现方法;以及如何通过网络转型,来促进业务转型,从而使网络运营商向综合运营商转变.利用公用交换电话网(PSTN)、下一代网络(NGN)和未来3G网络,固网运营商将发展成多网络综合运营商;利用现有PSTN用户规模和业务,发展融合业务,形成差异化的竞争优势.NGN智能化解决了PSTN用户享受NGN业务覆盖问题,将促进PSTN用户与NGN用户无缝演进和融合.     

固定电话网的新趋势——固网信息服务系统

本文首先讨论了中国电信开展固网短信业务的必要性，然后分析了开展固网短信业务存在的问题，最后介绍了固网短信系统的构成。     

基于DSP的二网融合的可视电话系统

为实现话音无阻塞、视频图像清晰流畅且低延迟的可视通话,提出使用PSTN单独传送话音,使用IP网络单独传送通话者视频并在终端同步还原的方法及其DSP实现的要点,终端以PSTN的拨号呼叫信号或来电振铃信号作为视频呼叫的触发信号,并将其捕获封装为SIP的Invite消息发起呼叫以建立视频P2P连接,使用UDP报文传送RTP视频流。测试表明系统在带宽为256Kbit/s且IP网络无拥塞的条件下,视频实现了CIF分辨力,帧频30f/s(帧/秒),视频延迟小于60ms,通话话音无阻塞,且话音通信与任何现有话音终端兼容,用户使用习惯如电话号码和拨号方式则不需任何改变。     

Granulated broadband networks

A new ATM platform concept can accelerate the introduction of broadband services with enhanced integration of existing narrowband services-including POTS. In order to reduce initial costs for broadband services, an ATM-based platform must be constructed for various services. In particular, existing public switched telephone network (PSTN) services can be economically accommodated in ATM-based broadband networks, and the costly part of the network could be shared by dominant PSTN services. This article proposes a granulated broadband network (GBN) concept as an intermediate platform for achieving broadband aspects of ISDN (B-ISDN)     

基于CATV的VOD及其多媒体信息系统方案

介绍一种以现有的ＣＡＴＶ网为下行通道，ＰＳＴＮ网上行信道向用户提供简单ＴＯＶＤ业务和多媒体信息业务的方案。     

B－ISDN与现有网络互连的研究

本文主要围绕Ｂ－ＩＳＤＮ与现有各种网络（如ＰＳＰＤＮ、ＰＳＴＮ、ＬＡＮ等）的互连问题展开讨论，并针对不同的应用场合提出了相应的互连解决方案。     

Talk about a change [VoIP replacing PSTN]

The rapid rise of Internet telephony services means that existing telecoms networks could soon be redundant. This paper examines the technological and financial issues concerning voice over Internet protocol (VoIP) and the probability of it substantially replacing existing public switched telephone networks (PSTN) within the next few years.     

NGN和IMS对承载网QOS方面的要求和QOS保障技术

在通信运营商推行的光进铜退和网络演进改造过程中,大量的PSTN用户割接到了NGN或IMS网络;还有大量的企事业单位也在逐步使用企业级的NGN或IMS设备更新换代原有老化的传统的DID交换机设备。现有的PSTN网络以电路交换为特征,在支持语音通信上颇有优势;NGN或IMS网络为保证语音通信的质量,对其承载网在QOS保障方面有明确的指标要求。本文论述了NGN、IMS对承载网QOS方面的指标要求以及QOS的相关保障技术。     

Evolution of telecommunications in Russia

The current status of Russia's telecommunications infrastructure does not correspond to the country's increasing demands. The creation of a commercial digital overlay network is apparently the only possible solution to provide modern telecommunications services. This article describes the following aspects of the evolution of telecommunications in Russia: a classification of the main specific features of the existing telecommunications networks; an analysis of the telecommunications statistics and forecasting of the main characteristics; likely future scenarios of the evolving telecommunications system; and the main telecommunications projects that will be carried out in the nearest future. Until now, the public switched telephone network (PSTN), a unique system providing basic dialogue services (speech, data transmission, etc.), was the single solution to provide national telecommunications. For this reason, we first describe the main features of the Russian national PSTN     

IP电信网技术研究

文章讨论了IP电信网存在的诸多关键技术问题。指出IP电信网有能力综合现有全部电信业务,可以提供与传统电信网相同的安全性和相同的服务质量,而且不会因此而加大IP网的复杂性;IP电信网的关键问题不是可逾越的,有相当技术业已存在,这些问题是可以近期内解决的。     

True number portability and advanced call screening in a SIP-basedIP telephony system

Custom local area signaling service features offered in the PSTN have certain limitations due to the closed nature of PSTN network signaling. The adoption of telephony over IP (IP telephony) will enable a new paradigm of services and features that are not possible to implement in today's PSTN. This is especially the case for services that make use of personal, trusted information, which can be provided by a user's personal digital assistant. We demonstrate how personal information can be coupled with an IP telephony service to provide user-customized call handling by the network. In particular, we describe a demonstration architecture that includes Ethernet-attached phones running SIP, with an interface to synchronize with PDAs that supply personal information. The proposed architecture is quite flexible; it can support enhanced versions of the current PSTN and private branch exchange services, in addition to many new features and services. We describe true number portability and advanced call screening as examples of new services in a hybrid PSTN/IP telephony environment     

Two-way calling public CT2 telepoint system

In most current implementations of CT2 telepoint systems, only handset initiated calls are allowed. This paper describes a design to allow two-way calling for the CT2 public telepoint system with minimal modifications to the current CT2 infrastructure and the public switched telephone network (PSTN). The design makes use of centralized databases in the home location register (HLR) and visitor location registers (VLR) to track the location of handsets. This location information is stored in the VLR and HLR, and is used by the PSTN to route incoming calls destined for CT2 handsets to the appropriate CT2 telepoint base station (TBS). The TBS connect to the PSTN local exchanges (LE) through the integrated services digital network (ISDN) basic rate interfaces (BRI) for fast out-of-band signaling. We present simulation results of the system with the objective of determining where congestion might occur within the system and to understand the impact of the new implementation on the PSTN. The results indicate that the performance of the system will be limited by the VLR processing speed and the number of ISDN BRI's connecting the ISDN front end (IFE) to the PSTN     

软交换在PSTN网络演进中的应用策略

文章概要分析了PSTN网络现状及基于软交换的下一代网络,从网络演进、业务演进和运营支撑的演进等主要方面阐述了软交换在PSTN网络中的应用。     

基于HLA的公用电话网实时半实物仿真系统设计

文中介绍了以一种HLA-RTI为基础环境的公用电话网实时半实物仿真方法，通过构造HLA仿真联盟成员，将OPNET中建立的PSTN七号信令模型，引入了RTI平台，设计实现了PSTN硬件数据采集模块，实时收发PSTN数据，并搭建了仿真实验平台，实验证明该平台仿真效果好，拟真度高。随后，对仿真时间推进算法作了适当改进，降低了系统的计算负荷。     

固网智能化创新业务的研究

固网智能化为PSTN提供丰富业务创造了条件,能进一步挖潜PSTN的潜力,为PSTN赋予了新的活力.本文提出三个固网智能化创新业务:多号彩振、电话广告和变声业务,并在其业务定义、业务功能、技术实现方案、产品定位与目标用户等方面进行了研究.     

中国固网通信设备制造业的过去,现在与未来

介绍了我国传统固定电话网通信设备制造业的发展简史,对2010年1—2月我国的固网通信设备制造业的产业规模,赢利情况以及2010年第1季度我国的主要传统固网通信设备产量进行了分析,得出了我国传统固网通信设备制造商应该利用设备更新换代的机会,向新型固网通信设备制造商转型的建议。