基于公众蜂窝网的PTT业务标准研究

基于公众蜂窝移动通信网络的PTT业务称为PoC业务。由于PoC业务呼叫建立时间短,能够发起半双工方式的群组呼叫,从而成为备受瞩目的移动通信业务。本文主要介绍了PoC业务标准发展情况,并结合IMS网络结构开展对PoC业务的研究,从而说明PoC业务的网络框架,以及PoC对IMS的需求和IMS对PoC的支持情况。     

浅议数字集群和3G网络PoC业务的关系

数字集群和3G网络PoC业务都可以实现PTT功能。数字集群是基于信令通道的解决方案，在通话过程中，语音数据和信令数据都汇集到事先建立好的通道上传输；3G网络的PoC业务采用VoIP技术，核心网基于IMS架构，在移动终端和业务应用服务器间运行高层信令协议，把话音数据捆绑到IP链路上。数字集群和PoC在技术实现、网络要求和市场定位方面都有很大的差异。数字集群主要应用于移动专网，而PoC业务主要是公众蜂窝移动通信系统的无线增值业务。     

浅议数字集群和3G网络PoC业务的关系

数字集群和3G网络PoC业务都可以实现PTT功能。数字集群是基于信令通道的解决方案,在通话过程中,语音数据和信令数据都汇集到事先建立好的通道上传输；3G网络的PoC业务采用VoIP技术,核心网基于IMS架构,在移动终端和业务应用服务器间运行高层信令协议,把话音数据捆绑到IP链路上。数字集群和PoC在技术实现、网络要求和市场定位方面都有很大的差异。数字集群主要应用于移动专网,而PoC业务主要是公众蜂窝移动通信系统的无线增值业务。     

浅议数字集群和3G网络PoC业务的关系

数字集群和3G网络PoC业务都可以实现PTT功能。数字集群是基于信令通道的解决方案，在通话过程中，语音数据和信令数据都汇集到事先建立好的通道上传输；3G网络的PoC业务采用VoIP技术，核心网基于IMS架构，在移动终端和业务应用服务器问运行高层信令协议，把话音数据捆绑到IP链路上。数字集群和PoC在技术实现、网络要求和市场定位方面都有很大的差异。数字集群主要应用于移动专网，而PoC业务主要是公众蜂窝移动通信系统的无线增值业务。     

PoC业务低时延建链协议研究与设计

PoC(Push-to-talk over Cellular,亦即无线一键通)是一种基于移动蜂窝网络的PTT语音业务。PoC支持一对一的个人呼叫和一对多的群组呼叫。当前基于2.5 G/3G的PoC业务面临的一个普遍问题便是呼叫建立时延过长,用户体验和传统的点对点语音业务相比有较大差距。针对PoC会话建立时延过长的问题,结合SIP压缩与扩展,本文提出了适用PoC业务的低时延建链协议,同时通过仿真验证了低时延建链协议对于PoC会话建立时延性能的改善。     

3G移动PoC实现技术

移动一键通(PoC)业务是3G的重要特色业务。PoC的实现有基于PS和基于IMS两种方式。文章从分析PoC的业务特点出发,介绍了PoC业务的功能、协议结构和标准化情况,比较了两种实现方式的实现要点,特别是详细分析了3G环境下基于IMS实现方式的实现机制和流程。最后,对PoC业务的应用和发展作了一个展望。     

PoC数据业务开展的几点思考

文章介绍了基于IMS的PoC业务的特性与市场背景,通过与传统数字集群、移动Fetion以及Skype等业务比较,对PoC业务的客户体验、通信运营、技术支撑等业务开展的关键问题进行了分析和阐述。只有在业务开展中突破其中的瓶颈,PoC业务才能真正成为3G网络中的杀手级应用。     

基于Parlay API的多方呼叫业务的设计与仿真实现

文中分析了3G蜂窝移动通信网络中增值业务设计的重要性,提出了一种基于Parlay API技术的3G移动通信网络多方呼叫业务的程序设计方法,并在NRG仿真器上对该业务进行了仿真实现,验证了遵循parlay组织提出的开放API开发电信增值业务的可行性和简单性.最后,分析了3G网络中多方呼叫业务的实际运作效果及其市场价值.     

基于IMS的PoC技术探析

IMS是下一代网络的主流解决方案,着重于解决多网融合的问题。PoC业务是定义在公众蜂窝网络上的PTT业务,具有广阔的市场前景。文章介绍了基于IMS的POC业务的主要特性、体系结构和典型业务的信令流程,提出了在IMS域上PoC的业务实现方案。     

利用IMS域实现3G移动通信业务

提供丰富、便捷、质优价廉的业务是3G移动通信系统成功商业运营的关键,因此建立先进、高效、灵活的业务平台至关重要。文章介绍了IMS的基本含义及功能,重点论述了基于IMS的3G移动通信业务平台的体系架构,讨论了基于IMS域的3G移动通信业务的实现和成功应用。     

一种基于IMS域的移动增值新业务:PoC

文章介绍了一种基于IMS域的移动增值新业务:无线一键通(PoC)业务,讨论了其实现方案,并对典型PoC业务的SIP信令交互流程进行了描述.在对PoC技术的优缺点进行分析的基础之上,文章探讨了未来PoC业务的用户定位问题,得出结论:企业级用户群、社团用户群以及主要由白领和青少年组成的个人用户群将是PoC业务的市场主体.文章认为PoC系统完全可以充当彩信、即时消息、状态呈现、图片收发等众多新业务的工具,将像短信业务那样,最终形成终端厂商、设备厂商、服务提供商、运营商合作共赢的PoC产业价值链.     

3G IP Multimedia Subsystem based framework for lawful interception

Issues related to lawful interception, such as invasion of privacy and efficient investigation, are presently at the forefront of social consciousness. Interception technology has to consistently evolve in order to keep pace with new and varied network structures. Thus, standard lawful interception documents that are appropriate for the existing PSTN, 2G and 3G, and packet-based communication are being proposed. In particular, newly arising services based on IP Multimedia Subsystems (IMSs) that support multimedia streaming, data transmission, and voice over IP, make lawful interception even more imperative. In this paper, we propose an architecture for IMS/Session Initiation Protocol based Lawful Interception (LI) in wireless 3G networks. We also propose LI techniques that are differentiated according to the IMS characteristics where content service providers are separated from network providers. Using the standards of dynamic triggering technologies for commissioning the authority to intercept among multiple network providers as a basis, we analyze IMS architecture and service operation methods. We then propose an LI architecture that is appropriate for IMS services. In addition, we present the results of a quality of service performance analysis conducted on our proposed interception architecture for various numbers of IMS users.     

下一代网络业务开发和控制平台的标准化研究

下一代网络对业务的快速开发和部署需求越来越迫切,需要在网络能力开放的基础上进一步开放业务的能力.本文对与下一代网络的业务开发和控制相关的两大主要标准化组织3GPP和OMA进行了详细研究,阐述了3GPP IMS作为下一代网络业务开放的统一的控制平台的工作机制,分析了OMA业务环境OSE的概念和思想,并详细分析了OSE与IMS的关系.最后以PoC业务为例阐明了下一代网络的业务开发模式及业务之间的调用关系.     

基于IMS的CDMA视频通信业务关键技术研究

IP多媒体系统（IMS,IP Multimedia Subsystem）是核心网的发展方向,视频通信（VT,Video Telephony）业务是移动网络3G时代的典型应用。针对视频通信业务需求,给出了基于IMS网络实现码分多址（CDMA,Code Division Multiple Access）网络VT业务的方法,并就业务现网实施过程中的关键问题进行了分析研究,提出了操作性较强的解决方案,为运营商部署相关业务提供了技术参考。     

基于GPRS的PoC系统的设计与实现

本文介绍了PoC这种新型的语音业务及其体系结构,并分析了在现有的GPRS网络上实现PoC业务的体系结构.分析了PoC系统的组网,对PoC系统进行了设计与实现.     

5G用户语音业务解决方案

语音业务仍然是5G时期的重要业务之一,3GPP标准已明确基于IMS网络为5G用户提供语音业务。结合5G网络部署路线的选择,分析了不同路线选择下的5G语音业务解决方案,以期为运营商在网络部署时提供参考。     

Dimensioning and optimization of push‐to‐talk over cellular server

The PoC (push‐to‐talk over cellular) application allows point‐to‐point or point‐to‐multipoint voice communication between mobile network users. The related work over PoC focuses on the performance analysis only and is ignorant about dimensioning a PoC controller to optimize revenue for service providers. In this paper, we dimension a PoC service with the assumption that the network grade of service is provided. The on‐demand sessions should have access priority over pre‐established sessions. A PoC controller should be able to terminate a PoC session based on an optimal timer. Moreover, the number of simultaneous session initiations by a PoC client is also a configurable parameter. We derived relations to provide access priority to special PoC sessions based on available transmit/receive units (TRU) and threshold level. Load sharing expressions are reported for a PoC controller using the Lagrange multiplier technique. A simple relation to control the PoC session timer is proposed. Finally, the derivation of maximum number of allowable simultaneous sessions is depicted using two‐state Markov models. Numerical results have been computed with the corresponding derivation to provide a useful insight into the system behaviour. A PoC service can benefit from these optimal values of our work during the busy hour. Copyright © 2007 John Wiley & Sons, Ltd.     

一种新的面向IMS网络的SIP协议栈

IMS是3G系统中核心网的重要部分,由SIP提供的会话发起能力建立起端到端的会话,并获得所需要的服务质量。本文基于有限状态机提出了一种新的面向IMS网络的SIP信令协议栈。通过在软终端上的功能、性能和可靠性测试,本文提出的SIP协议栈能够有效地完成多媒体通信功能。     

A client‐side design and implementation for push to talk over cellular service

This paper proposes a client architecture for the push to talk over cellular (PoC) service based on the open mobile alliance (OMA) PoC specifications v1.0 release. We show that most standard VoIP modules can be reused for the PoC client, and the VoIP software can be easily extended to support PoC service. Then we present the detailed message flows between the PoC client and other network entities in the PoC system. A PoC client prototype has been implemented in the Industrial Technology Research Institute (ITRI) and National Chiao‐Tung University (NCTU) Joint Research Center. Copyright © 2006 John Wiley & Sons, Ltd.     

The IMS service platform: a solution for next-generation network operators to be more than bit pipes

As third-generation (mobile) networks (3G networks) become a commercial reality, strong movements are emerging in the direction of a common infrastructure based on the Internet protocol (IP). The users' mobile devices are like another IP host connected to the Internet. In such a scenario, the network operator infrastructure is degraded to bit pipes. To avoid this, the 3G partnership project (3GPP) and ETSI TISPAN have designed IP multimedia subsystem (IMS), a service platform that aims to place the network operator again in the central role of service provisioning. In this article we examine IMS from a mobile operator's perspective and analyse its possible adaptation to the next-generation networks.