基于IMS的固定移动融合研究

固定移动融合技术是下一代网络的研究热点之一,以IP多媒体子系统为核心架构的固移融合成为业界广泛认同的发展方向。本文对IP多媒体子系统的核心架构进行了介绍,并在其基础上对固移融合的分层体系结构进行了分析,最后讨论了实现固移融合的几项关键技术。     

使用SlPservlet1.1技术实现IMS网络Presence呈现服务器

2002年,3GPP组织在3GPP的Release5版本提出IMS(IP多媒体子系统),作为UMTS的核心网演进方案.移动通信正从2G向3G演进,不但在无线接入网中采用了更先进的宽带CDMA技术,在核心网络方面也正从电路交换向分组交换转变.而IMS是基于SIP协议的在承载网络上附加的网络,是支持IP多媒体业务的口多媒体子系统.为未来的多媒体应用提供一个通用的业务使能平台.     

固定移动网络融合和运营商的应对策略

固定和移动网络融合的本质是业务提供与接入技术和终端设备相独立。IP多媒体子系统（IMS）是3GPP在Release 5版本提出的与接入技术无关的支持IP多媒体的子系统。基于IMS的固定与移动融合将是网络演进的方向。在网络完全升级到IMS之前，运营商的应对策略是首先应用/业务层和业务传送层进行融合，借助统一的用户数据和统一、开放、标准的业务平台开展固定移动融合业务，为下一步演进到IMS做好准备。     

基于IMS的早期媒体类业务

通过对基于IP 多媒体子系统(IMS)网络的多媒体彩铃业务与多媒体彩像业务在业务协作方面的分析,指出现有早期媒体类业务解决方案中存在的问题,提出一种基于early-session的扩展方式,可以在同一个IMS呼叫实例中支持多个早期媒体类业务,并给出IMS终端的呼叫模型。     

使用SIPservlet 1．1技术实现IMS网络Presence呈现服务器

2002年,3GPP组织在3GPP的Release5版本提出IMS（IP多媒体子系统）,作为UMTS的核心网演进方案。移动通信正从2G向3G演进,不但在无线接入网中采用了更先进的宽带CDMA技术,在核心网络方面也正从电路交换向分组交换转变。而IMS是基于SIP协议的在承载网络上附加的网络,是支持IP多媒体业务的IP多媒体子系统。为未来的多媒体应用提供一个通用的业务使能平台。     

软交换的内涵与发展趋势

传统的以电话业务为基础的电路交换网络难以快捷、灵活地提供丰富的业务，能够提供集语音、视频、数据为一体的多媒体综合业务的下一代网络（NGN：NextGenerationNetwork），将真正实现宽带窄带一体化、有栈元线一体化、有源无源一体化、传输接入一体化的目标。支持全业务的软交换正是下一代网络的核心技术。软交换吸取了IP、ATM、IN、TDM等众家之长，完全形成分层的全开放的体系架构，方便地在网上引入各种业务，并使得现有网络与下一代网络充分融合。本文阐述了软交换的内涵、现状和发展趋势，并分析了软交换的市场前景和面临的技术难点。     

RollingStreamIPTV整体解决方案

RollingStream是一套开放的、支持多业务、多服务终端的宽带多媒体业务平台,通过IP网络传送广播级视频质量的,视频和互动娱乐服务,可以为服务运营商提供端到端数据、语音、多媒体(Triple-play)业务。1.RollingStream组成图1RollingStream特点(1)开放式体系架构◆丰富的媒体格式     

基于IP网络IPTV技术的应用研究

本文首先介绍了数字电视与IPTV的概念,指出在IP网络中传输实时视频、音频数据存在的问题,分析了IPTV应用的关键技术MPEG-4;并提出一种IPTV技术的页面实现,IPTV提供面向普通消费群体的视频及多媒体服务,适合在当前及未来基于IP的运营网络上推广。     

基于IMS的电信网融合

由3GPP提出的IP多媒体子系统提供了一个在全IP移动通信网络中支持多媒体通信的系统结构。文章简要说明了固定网和移动网向下一代网络演进的过程，提出了基于 IMS融合的网络架构，提出了固定网和移动网融合需要解决的问题。     

专用网络中FMC的初步研究

介绍了固定移动融合（FMC）的背景、定义、特点,对FMC实现技术之一的IP多媒体子系统（IMS）的特点和架构进行了阐述。结合某专用网络应用需求,对IMS体系架构及会话消息进行了适应性改进,提出了基于IMS架构实现某专用网络FMC的系统框架,最后给出了专用网络基本话音业务的会话控制流程。     

Adaptive IPTV services based on a novel IP Multimedia Subsystem

Heterogeneous communication devices are emerging and changing the way of communication. Innovative multimedia applications are now accessible through these embedded systems. The 3GPP IP Multimedia Subsystem (IMS) provides a basic architecture framework for the Next Generation Network (NGN) supporting the convergence platform for service provisioning in heterogeneous networks. ETSI TISPAN standardization effort focuses on delivering IPTV services on such platform. Nevertheless, IPTV on IMS standardization suffers from a lack of efficient user-centric network management mechanisms as the end-user may consume IPTV service from different access networks, on different mobile devices, at anytime. User’s Perceived Quality of Service (PQoS) or Quality of Experience (QoE) of IPTV service may also suffer from wireless access network impairments. This paper introduces new functionalities in IPTV over IMS architecture which optimize satisfaction of the end-user and resource utilization of the operator’s networks. A context-sensitive User Profile (UP) model is used to deliver IPTV streams adapted to the user’s environment. In order to optimize the operator network usage, the impact of spatiotemporal dynamics of the video content on the deduced perceptual quality is considered. A Multimedia Content Management System (MCMS) is proposed to perform dynamic cross-layer adaptation of the IPTV stream based on PQoS measurements at the end-user side.     

QoS Control for NGN: A Survey of Techniques

This article presents an overview of standards and a survey of recent work on quality of service (QoS) control of next generation networks (NGNs). We outline primarily standardized QoS control architectures with respect to the service and transport strata of NGN. In the service stratum, QoS parameter negotiation using core IP multimedia subsystem (IMS) procedures is described. In the transport stratum, the resource control and admission schemes of IMS (3GPP), resource admission control function (ITU-T), and resource access control system (ETSI/TISPAN) are explained and compared with each other in terms of QoS coverage and number of required signaling messages. In addition, we give a survey of papers on QoS control architectures, which further strengthen existing standards by adaptively managing QoS modification according to user’s QoS changes and consistent QoS support for mobile users. Finally, we conclude this article with a discussion of further work of the QoS control for NGN.     

IPTV architecture for an IMS environment with dynamic QoS adaptation

This paper describes the development, implementation and evaluation of a SIP based IPTV architecture with a new dynamic QoS adaptation method and signaling structure. The implemented QoS adaptation method allows dynamic updates of session parameters, maximizing the QoE and turning the solution suitable for live multimedia streaming, independently of the cast mode (unicast or multicast). The new SIP signaling structure, for session and media control, was developed following an All-SIP approach and a hybrid SIP+RTSP approach, both suited for an IMS environment, in order to compare the system behavior and performance using either approach. The details of both the IPTV Application Server and the IPTV Client prototypical implementations are described, as well as the results of field tests carried out across different Fixed and Mobile access networks for each of the signaling structures. The proposed IPTV architecture revealed to be suitable for scalable converged networks, due to its flexible multimedia delivery of personalized streams over a variety of network infrastructures, namely, Mobile radio networks.     

基于IMS的移动多媒体广播时移系统信令设计

提出一种基于IMS的移动多媒体广播时移系统架构,该架构融合广播网络和无线移动通信网络,为移动多媒体广播提供时移服务,实现服务与接入无关。设计基于SIP的时移信令流程来完成对时移业务的支撑。利用排队论方法对时移请求信令延迟进行理论分析,结果表明信令延迟能够满足实时性需求,证明该系统是完全可行的。     

基于IMS的E2E QOS控制机制

3GPP提出的IMS用于提供各种实时多媒体业务,未来的实时多媒体服务将以视频、音频以及视频、音频的混合为主,对于实时性和延迟的要求很高,需要E2E的QOS的支持。文章分析了现有的IMS的QOS机制的实现以及存在的不足,提出了一种新的基于策略的E2EQOS机制。新的机制主要实现了IMS中的各个层次间的相互协作、SIP协议的扩展和PDF功能的改进,实现了对多媒体业务实时性的提高并且缩短了延迟。     

Interworking of heterogeneous access networks and QoS provisioning via IP multimedia core networks

Moving towards packet networks, where IP will have a prominent role, constitutes nowadays a widely accepted perception of future communications, the first instance of which has begun to materialise with the IP multimedia core network subsystem (IMS). By specification, IMS is the first implementation towards reaching converged communications which allows users to communicate with video, audio and multimedia content, via any fixed, mobile and wireless access network type, with controllable QoS. To enable IMS communications across heterogeneous networks, incorporating UMTS, WLAN and fixed IP access points, 3GPP and ETSI’s TISPAN currently work on schemes for controlling bandwidth allocation at the service level by employing logical interfaces that carry SIP messages. This article analyzes how interconnection between such heterogeneous networks may be performed on real platforms. In this effort, special attention is paid to the way the various interconnection possibilities can affect end-to-end QoS provisioning.     

基于以太网的IP接入网络的QoS技术研究

接入网的QoS机制是实现NGN中端到端的QoS保证的重要因素，而以太网是最为主要的接入网技术。本文讨论了ITU NGN专题组NGNFG中关于基于以太网IP接入网络的QoS的控制体系结构的研究进展，在基于以太网IP接入网络的定义和参考模型中分析了基于以太网IP接入网络的QoS问题，本文阐述了基于以太网的IP接入网络的支持动态和每个会话控制的QoS控制过程和提出了有关的接口以及它们的需求。     

The IP multimedia domain: service architecture for the delivery of voice, data, and next generation multimedia applications

The IP Multimedia Subsystem (IMS) is defined by the 3 ^rd Generation Partnership Project (3GPP) as a new core network domain. IMS provides a service control platform that allows creation of new multimedia and multi-session applications utilizing wireless and wireline transport capabilities. In this paper we will cover the concepts and standards defining IMS and review the network architecture from a mobile perspective. We will see how IMS interacts with the Packet Switched Domain (e.g. Wireless LAN, GPRS, and UMTS networks), the Internet, and application services. Then we will examine the key IMS capabilities and show how they can be combined to create new mobile IP services. Finally, we present a software architecture, which is enabled by IMS and allows development of unique applications (with multimedia/multi-session functionality, single/multi-user, service to user). The software architecture is illustrated by an example of a prototype application. This work was done when the author was with Siemens Communications Inc., Boca Raton, FL     

The IP multimedia domain: service architecture for the delivery of voice, data, and next generation multimedia applications

The IP Multimedia Subsystem (IMS) is defined by the 3^rd Generation Partnership Project (3GPP) as a new core network domain. IMS provides a service control platform that allows creation of new multimedia and multi-session applications utilizing wireless and wireline transport capabilities. In this paper we will cover the concepts and standards defining IMS and review the network architecture from a mobile perspective. We will see how IMS interacts with the Packet Switched Domain (e.g. Wireless LAN, GPRS, and UMTS networks), the Internet, and application services. Then we will examine the key IMS capabilities and show how they can be combined to create new mobile IP services. Finally, we present a software architecture, which is enabled by IMS and allows development of unique applications (with multimedia/multi-session functionality, single/multi-user, service to user). The software architecture is illustrated by an example of a prototype application. This work was done when the author was with Siemens Communications Inc., Boca Raton, FL