基于IMS的多媒体彩铃业务解决方案

IMS（IP多媒体子系统）最初是3GPP组织制定的3G网络核心技术标准，目前已被ITU-T和ETSI认可，纳入NGN的核心标准框架，并被认为是实现未来FMC（固定／移动网络融合）的重要技术基础。IMS是一个全IP的网络架构，采用SIP协议进行控制，实现移动性管理、多媒体会话信令和载体业务传输，实现端到端的IP业务。此外，IMS还具有普通业务采用归属服务控制，接入独立，业务、控制、承载层完全分离等特点。[第一段]     

基于IMS的多媒体彩铃业务解决方案

一、IMS系统特点 IMS(IP多媒体子系统)最初是3GPP组织制定的3G网络核心技术标准,目前已被ITU-T和ETSI认可,纳入NGN的核心标准框架,并被认为是实现未来FMC(固定/移动网络融合)的重要技术基础.IMS是-个全IP的网络架构,采用SIP协议进行控制,实现移动性管理、多媒体会话信令和载体业务传输,实现端到端的IP业务.此外,IMS还具有普通业务采用归属服务控制,接入独立,业务、控制、承载层完全分离等特点.     

IP城域网业务接入控制层业务备份技术探讨

越来越多的电信业务通过IP网络承载,对IP城域网的可靠性提出了极高的要求.业务接入控制层在IP城域网中是多业务融合承载的关键设备,在网络中承担着承上启下的功能.根据运营实践和业务测试,分析了业务接入控制层设备业务备份目前的技术现状,提出了在新型承载网络架构中构建高可靠性业务接入控制层的方法和建议.     

IMS及其演进趋势

IMS(IP多媒体子系统)以SIP(会话启动协议)作为主要呼叫控制协议,支持用户移动性管理,支持接入终端多样化,拥有开放灵活的业务环境,被认为是未来宽带业务的控制核心和实现FMC (固定/移动网络融合)的理想架构。对IMS体系架构进行了分析,探讨了IMS和软交换的相互关系,并给出移动网络和固定网络引入IMS的策略。     

宽带IP城域网网络重构探讨

宽带IP城域网流量增长迅速,承载业务种类繁多,并与终端宽带客户直接连接,城域网的网络重构直接奠定了"以DC(数据中心)为核心"的未来网络架构的基础。未来宽带IP城域网将分为核心层、区域核心层、汇聚层和接入层,并分阶段演进为两级DC(边缘DC+核心DC)、"软边缘+硬转发"的目标架构。运营商当前应重点做好通信机房局点专项规划、CO(中心局)机房重建等工作,并加快城域网SDN/NFV(软件定义网络/网络功能虚拟化)等新技术的试点和应用。     

通信网络发展趋势--固定移动融合

IP多媒体子系统（IMS）是FMC的最终架构,是网络演进的方向.在核心网络完全基于IMS融合之前,首先应在应用/业务层和终端接入层进行融合,借助统一的用户数据和统一、开放、标准的业务平台开展FMC业务,将是平滑演进到IMS的最佳途径.     

中国联通下一代网络的实践与思考

文章介绍了中国联通的多业务统一网络平台,包括多业务服务质量(QoS)保障的融合的承载平台、融合的软交换核心控制架构、多业务QoS保障的城域综合业务网络和基于IPv6的网络承载技术.依据中国联通在下一代网络(NGN)方面的实践,文章对多业务统一网络平台的先进性、效果与效益进行了总结,并指出了存在的问题.文章指出:由于未来NGN技术将向基于IP多媒体子系统(IMS)的NGN方向继续演进,同时网络承载层技术将逐步从IPv4过渡到IPv6,因此中国联通将积极探索基于IMS的NGN网络架构与组网模式,努力开展面向IPv6的应用实验与推广工作,特别是移动IPv6业务的开发和推进.     

高效承载IP网络ASON助力联通IP化发展

未来的网络架构将从垂直网络向水平网络演进,电信业务IP化是业界主流的发展趋势。简化网络、构建统一融合的IP承载网络是降低CAPEX、OPEX,追求综合低成本（TCO）的一个重要目标。IP承载网是一个多业务承载网络,不仅能够满足信令和语音业务承载要求,将来还可以承载精品大客户专线等业氛     

光纤接入规模推进对网络架构的影响

1 宽带接入网组网架构 随着电信网络向NGN的不断演进和IP化的发展趋势,接入网正朝着宽带化、IP化和综合化的方向发展.如图1所示,宽带接入网是城域网业务接入控制点(如BRAS/SR)以下、客户网关之间实现多业务融合承载的实体,可划分为汇聚层和接入层.     

全业务网络演进

从固定运营商和移动运营商的角度诠释了全业务运营的转型策略和网络演进的途径,并从业务层、控制层、IP承载层、接入/终端等方面着重介绍了全业务网络的演进。     

基于软交换的个人监控通信

网络的融合及终端智能化程度的提高，为个人监控通信的实现提供了条件。借助于M2M技术，软交换网络可以为个人监控通信提供理想的实现平台。基于软交换的网络架构和实现原理，个人监控通信系统可分为网络侧和用户侧两部分。网络侧设备包括软交换机、现场业务中心等，位于核心控制层和业务层；用户侧设备包括监控设备、现场设备、网关和现场控制平台，位于接入层和现场设备层。通过基于软交换的个人监控通信系统可以实现家庭自动化、公共服务、资源调度、安全监测以及社群互助等多种人机通信业务。随着机器智能的提高和网络的融合，将来个人监控还会不断完善和发展，极有可能成为未来通信的主流业务之一。     

ATM in MPLS-based converged core data networks

Services supported by asynchronous transfer mode account for the majority of data and Internet service revenues generated by carrier networks today. This is based on ATM's ability to support high availability services with quality of service. However, the influences of the Internet and a highly dynamic telecommunications market have raised demands for increased flexibility while controlling costs. Therefore, future carrier networks are likely to continue to be based on established technologies, such as ATM, as well as IP. In many cases, this is achieved through maintaining separate ATM and IP core networks, with the IP network supporting Internet services, while the ATM network continues to support guaranteed services such as private lines, broadband access, and video. In some cases, however, it can be advantageous for a carrier to transport segments of their ATM network over their IP network core; for example, to transport ATM traffic currently carried on leased facilities onto an IP network where the service provider owns the facilities. Developments in IP and MPLS-based traffic engineering and QoS may increase the ability of IP-based networks to support ATM services using MPLS. This article provides an overview of approaches enabling a network based on MPLS that naturally supports IP services to also support ATM services. The drivers and requirements for convergence on an IP/MPLS core network are presented, followed by an overview of the different approaches and associated challenges currently being debated in the standards bodies.     

PTN承载网业务规划

随着全业务的开展及基站IP化的逐步深入,分组化乃大势所趋,从核心网至接入网均向IP化方向发展,新的业务种类越来越多,业务类型正从单纯的TDM业务为主、2 Mb/s为颗粒向以数据业务为主、宽带接口过渡,城域传送网正面临着重新规划建设的繁重任务。分组传送网（Packet Transport Network）技术以分组为主要承载对象,将IP技术与传输网技术相融合,可实现对传统业务和各种新兴业务的统一承载,简要介绍了PTN的技术特点,重点分析了PTN承载网2G、3G主要业务的规划模型和原则。     

Service convergence using MPLS multiservice networks

Enterprises are increasingly using virtual private networks to interconnect remote sites. Traditionally, service providers have used ATM core networks to deliver layer 2 services such as frame relay, ATM, or TDM private lines, which enterprise customers have then used to build their corporate network infrastructure. Such services account for the majority of data service revenues today. However, pressure has increased on service providers to combine increased flexibility with reduced costs in the context of a highly dynamic telecommunications market. Service providers also need to generate new revenues from their IP network infrastructure, through new opportunities such as IP VPNs and virtual private LAN services, while simultaneously achieving operational efficiencies through the convergence of all of their services on a common MPLS backbone. New access and metro network technologies, such as Ethernet, are also emerging that can be used to deliver these new services to enterprise customers alongside ATM and frame relay access. This must be achieved while also supporting existing technologies such as ATM, which continue to deliver highly profitable services. This article discusses the technical challenges in meeting the often conflicting requirements of delivering both traditional layer 2 services and new layer 3 services on a converged MPLS network. We show how both network and service interworking are required, and how these must operate at the user, control, and management planes to enable profitable services to be delivered over the new converged network. The different solutions being defined in the standards bodies are described, and the distinct scenarios they address are explained.     

IMS与固定移动网络的融合

IP多媒体子系统(IMS)采用SIP协议进行呼叫控制,与接入无关,支持各种综合业务,因此,ETSI和ITU-T已将其作为NGN的核心结构.首先简要介绍了IMS的网络架构及其特点,分析了基于IMS实现固定移动网络融合的优势,提出了基于IMS的网络融合方案,并指出这种融合方案所面临的问题与挑战.     

Advances in Wireless Video Delivery

This paper reviews practical video delivery technologies, examining existing mobile networks, commercialized or standardized transport, and coding technologies. Compression efficiency, power dissipation, and error control are intrinsic issues in wireless video delivery. Among these issues, error control technologies are evaluated at four layers: 1) layer-1/2 transport; 2) end-to-end transport layer such as TCP/IP or RTP/UDP/IP; 3) error-resilience tool and network adaptation layer) and 4) source coder layer. Layer-1/2 transport tends to provide two distinct conditions: one quasi-error-free, in which upper layer error control technologies show a limited improvement, and one with a burst of errors during the fading period, in which the adaptability of error control is essential. Emerging mobile network quality of service will have a large variation of bandwidth and delay. Thus, adaptive rate control and error recovery are identified as more crucial issues for future research.     

IPTV--三网融合的开端

IPTV与目前的3个运营网（有线电视网、Internet和电信网）及其业务直接相关。但不同运营商对IPTV业务有不同定位。电信运营商认为IPTV业务体现于电视节目在IP网中的组织和传送形式，有线电视网络运营商认为IPTV业务是利用有线电视网来提供数字电视节目和电视节目以外的信息服务。由于IPTV业务分为广播业务和交互型业务两大类，支撑这两类业务的承载网也相应地分别采用单向广播网和双向交互网，因而在承载网层很难融合。融合工作将在业务层发生，即充分利用已经存在的两个承载网来经济、高效地发展业务。IPTV中既拥有广播型业务，又拥有组播型业务，还拥有交互型业务，将是三网融合的开端。     

未来电信竞争政策--一个基于IP网络的分层政策模型

电信管制政策历来是基于传统业务类型划分，然而，技术和市场融合与新技术的涌现正在改变电信政策的制定和实施环境，从而导致政策在相似服务之间的不一致性和相应的政策扭曲，主要表现在市场竞争、技术、投资、互联和普遍服务等若千方面。通过引入一个与未来TCP／IP网络相对应的分层政策模型．例如将网络分为内容层、业务层、传输层和接入层，并以此为基础考虑政策制定和实施，可以解决以上所述扭曲和政策不一致性问题，从而更有效地促进市场竞争.     

On IP-over-WDM integration

Expanding Internet-based services are driving the need for evermore bandwidth in the network backbone. These needs will grow further as new real-time multimedia applications become more feasible and pervasive. Currently, there is no other technology on the horizon that can effectively meet such a demand for bandwidth in the transport infrastructure other than WDM technology. This technology enables incremental and quick provisioning up to and beyond two orders of magnitude of today's fiber bandwidth levels. This precludes the need to deploy additional cabling and having to contend with right-of-way issues, a key advantage. Hence, it is only natural that over time optical/WDM technology will migrate closer to the end users, from core to regional, metropolitan, and ultimately access networks. At present, WDM deployment is mostly point-to-point and uses SONET/SDH as the standard layer for interfacing to the higher layers of the protocol stack. However, large-scale efforts are underway to develop standards and products that will eliminate one or more of these intermediate layers (e.g., SONET/SDH, ATM) and run IP directly over the WDM layer. IP over WDM has been envisioned as the winning combination due to the ability of the IP to be the common revenue-generating convergence sublayer and WDM as a bandwidth-rich transport sublayer. Various important concerns still need to be addressed regarding IP-WDM integration. These include lightpath routing coupled with tighter interworkings with IP routing and resource management protocols, survivability provisioning, framing/monitoring solutions, and others     

本地传输网WDM组网策略

业务网IP化趋势的发展,带动了大颗粒数据业务需求的增加,TDM需求也随之逐步弱化,因此带来IP over WDM承载方式实现的可能。本文主要讨论本地传输网建设中骨干层和汇聚层上的WDM组网策略。