Towards Standardized and Automated Fault Management and Service Provisioning for NGNs

The IP Multimedia Subsystem (IMS), already widely recognized as a fundamental core component of Next Generation Networks (NGNs), enables proliferation of a huge variety of value added services. Simultaneous to the emergence of triple play services there is a strong need for establishing standardized methodologies for service fulfillment and assurance, maintaining service execution parameters at advertised levels. Traditional Operations Support Systems (OSS) are not adequate for managing NGNs. This work shows experiences gained from implementing OSS for NGNs. It describes a solution that combines extensive NGN development expertise with a new generation, of policy-based, service oriented OSS solutions in order to provide enhanced levels of automation and reliability to the NGN service delivery and session control environment. Primary focus of this approach is put on service assurance and service fulfillment mechanisms for remote monitoring, automated control and configuration of standard compliant IMS infrastructures, such as the Open Source IMS Core (OSIMS) based Open IMS Playground. This work describes state of the art NGN OSS design principles and knowledge attained by integration of standardized fault management as well as service and subscriber provisioning procedures showing how the full cycle from service deployment to service advertisement to service execution can be delivered in an automated way.

An IMS-based network architecture for WiMAX-UMTS and WiMAX-WLAN interworking

The IP Multimedia Subsystem (IMS) seems to be the technology that will prevail in Next Generation Networks (NGNs), since the interworking environment and the service flexibility that this technology offers to the currently deployed wireless broadband technologies makes it appealing to users, service developers and network operators. In this paper we propose a heterogeneous network model based on the IMS that integrates the Worldwide Interoperability for Microwave Access (WiMAX), Universal Mobile Telecommunications System (UMTS) and Wireless Local Area Network (WLAN) technologies and provides guaranteed QoS. We present the complete signalling flow concerning the authorization, registration, session set up and vertical handoff processes, as well as, an analytic model for cost analysis of the proposed architecture.     

Critical Issues for QoS Management and Provisioning in the IP Multimedia Subsystem

This paper presents state-of-the-art research efforts in implementing a Policy Based architecture for Quality of Service management and provisioning of network services in the IP Multimedia Subsystem (IMS). While Policy Based Network Management has been adopted by the Third Generation Partnership Project and the Telecoms & Internet converged Services & Protocols for Advanced Networks as the solution for managing QoS in the IMS, the proposed mechanisms are sorely lacking in many aspects. First, the policy logic and decision mechanism are not specified, nor is the actual resource allocation procedure. Second, while the IMS is being tailored as the Service Delivery Platform for Next Generation Networks many of the QoS provisioning solutions are designed specifically for UMTS as an access network and need to be enhanced to support other technologies. In the current specifications, 3GPP is already evolving to support Packet Cable, WLAN and WiMAX accesses, but their respective policy-related sections are still void. Furthermore the proposed solutions do not specify how the network processes user requests for services in the IMS infrastructure. This article analyses critical QoS management issues within the IMS, and proposes solutions by designing a Policy Decision Function, which is the central element in the policy architecture. These solutions are presented in a proof of concept implementation running in a real IMS testbed making use of the Open Source IMS Core and considering the management of QoS in different scenarios.

A vulnerabilities analysis and corresponding middleware security extensions for securing NGN applications

International standard bodies such as the Parlay Group, 3GPP (Third Generation Partnership Project), and ETSI TISPAN describe an applications middleware in the form of open service access (OSA)/Parlay Application Programming Interfaces and Parlay X Web Services which allow multimedia applications to be implemented on top of different fixed and mobile network types. These established middleware services are also applicable to the new IP Multimedia Subsystem (IMS) forming the heart of emerging next generation networks. The main objective of this kind of middleware services is to simplify and unify service creation and – as applications are realized in so-called application servers which can be flexibly connected to dedicated network gateways – also to expose available network capabilities to third parties. This results in an inherent increase of security threats and increases the risk of attacks on network resources. This article describes the security requirements and challenges to Web services-based NGN middleware. Based on this analysis the paper presents the middleware security mechanisms at application level providing end-to-end security based on standard such as XML Digital Signatures, XML Encryption and SAML (Security Assertion Markup Language). Furthermore, we propose additional security means in the form of intrusion detection and prevention (IDP) system protecting applications middleware against SQL injection attacks which are not mitigated by existing solutions.     

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.     

SIP协议在呼叫保持业务中的分析与实现

在NGN(下一代网络)中,SIP协议是重要的协议,在3GPP的R5中定义了IMS(IPMultimedia Subsystem)域,该域的所有实体均用SIP信令通信,同时R5必须能够与R4,R99兼容。由于在R4和R99中广泛采用BICC和ISUP信令,这样就要求在R5的功能实体中实现SIP与BICC和ISUP的互通。介绍了SIP协议,在呼叫保持业务中需要用的实体以及SIP和ISUP消息,然后阐述如何通过SIP和ISUP消息参数的设置来实现这个业务。     

下一代网络QoS策略仿真

下一代网络(NGN)的一个重要特点是在基于IP数据包的基础上实现了话音、视频和数据业务的融合,要在统一的网络上为用户提供特性不同的各类业务,服务质量(QoS)成为一个突出的问题。下一代网络提出了实现机理各不相同的几种QoS策略模型,从而满足用户对服务质量的需求。本文在计算机网络仿真平台上,通过对各种QoS策略进行分析和网络仿真设计,得到了实施各种QoS策略情况下网络延迟、抖动等网络性能参数,通过对仿真结果进行分析和比较,为下一代网络业务融合并实施QoS策略提供科学的参考。     

浅析移动核心网应对全业务运营的方案

本文首先分析了在全业务运营的形势下数据业务是未来业务发展的主流,然后提出移动核心网应对全业务运营的两个方案——NGN和IMS。最后在对两种方案进行了比较和分析的基础上,建议应优先采用IMS方案。     

A Review of Policy-Based Resource and Admission Control Functions in Evolving Access and Next Generation Networks

The IP Multimedia Subsystem (IMS) adopted in the core of Next Generation Networks (NGNs) promises to make network management easier by separating the control and the transport planes. Therefore, an interface between applications and the underlying transport network has been defined that offers a dynamic and efficient management of network resources based on a policy-based resource control engine. The resulting resource management framework enables the delivery of both the existing carrier grade existing and the next generation Quality of Service (QoS) sensitive services across operator-controlled networks using heterogeneous transport technologies. This review sheds some light into the policy control layer concept and the extended nomenclature introduced by current standardization works. The approaches of international standards development organizations, such as the Third Generation Partnership Project (3GPP), the International Telecommunication Union (ITU), the European Telecommunications Standards Institute (ETSI), the WiMAX Forum, and CableLabs are reviewed and compared with each other revealing the common architectural trend. Challenges and works in progress of NGN resource management towards Fixed and Mobile Convergence (FMC) are discussed as well.

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.     

电信业有关NGN标准化工作进展

对国际电信联盟（ITU）及国内外电信行业有关下一代网络(NGN)的标准化工作进展情况进行了全面的分析与综述,内容涉及电信业 NGN的概念与内涵以及相关工作的标准化进程与前景。重点讨论了软交换技术、IP多媒体子系统（IMS）和基于MPLS的IP承载网相关的技术。最后指出：互联网技术给传统的电信网络运营商既带来挑战,也带来机遇,NGN的实现是一个长期的过程,成熟技术与高性价比的技术将最终占据主导地位。     

一种可支持多种多媒体业务的基于IMS的IPTV架构

IP多媒体子系统用于实现端到端的IP多媒体通信,具有接入无关性、对各种接入技术广适性的特点,因此,下一代网络采用IP多媒体子系统作为核心架构.提出一个基于IP多媒体子系统的IP电视架构,在IP多媒体子系统核心模块的基础上,以一组互相独立的基于会话初始化协议的功能模块构成应用服务器,并设计了能够支持和提供不同IM S业务的客户端与内容提供商端,使该IPTV框架可以在下一代网络上支持基于IP多媒体子系统的包括IPTV业务在内的多种多媒体业务.     

基于Web Services Binding和Java Component的SCA规范构建SOA

如何充分利用原有系统的资源,建立开放灵活、低代价的系统已成为信息化建设的关键。面向服务的体系结构（SOA）为解决分布式环境中软件重用、扩展和提高软件开发效率提供了解决方案。WebServices是构建SOA的核心技术,服务是SOA的基本单元;采用基于Web service Binding与Java Component的SCA规范构建SOA,能自然有效地实现服务间的松散耦合。结合电信项目开发探讨了SOA的有关概念与技术,并给出了在国产Linux环境下基于Web service Binding和Java Component的SCA规范构建SOA的部分实现。     

A user-centric approach to service creation and delivery over next generation networks

Next Generation Networks (NGN) provide Telecommunications operators with the possibility to share their resources and infrastructure, facilitate the interoperability with other networks, and simplify and unify the management, operation and maintenance of service offerings, thus enabling the fast and cost-effective creation of new personal, broadband ubiquitous services. Unfortunately, service creation over NGN is far from the success of service creation in the Web, especially when it comes to Web 2.0. This paper presents a novel approach to service creation and delivery, with a platform that opens to non-technically skilled users the possibility to create, manage and share their own convergent (NGN-based and Web-based) services. To this end, the business approach to user-generated services is analyzed and the technological bases supporting the proposal are explained.     

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。     

Supporting NGNs Core Software Services: A Hybrid Architecture and its Performance Analysis

In the last few years telco providers are striving to migrate their services from the traditional Public Switch Telephone Network to so called Next Generation Networks (NGNs) based on standard IP connectivity. This switch is expected to produce a cost degression of 50% for CAPital EXpenditure, while OPerating EXpences remains fairly stable due to network management and energy costs. At the same time, the instantiation of new telco services (Voice over IP, video conferencing, etc.) and the support of third party applications (such as support to smartphone applications, etc.) are expected to produce a big increase of the load of a telco provider at the core level. The goal of this work is to show how management and energy costs can be effectively reduced by leveraging autonomic approaches to move some NGN services toward the telco network edge while still providing Quality of Service (QoS) levels comparable with those provided by a traditional fully-managed infrastructure. This is done by taking into consideration the increase of the load of such services that is expected to raise by one order of magnitude in the near future. Specifically, we propose a hybrid architecture letting telco administrators reduce the number of servers in the provider managed network by exploiting home devices in the computation and by organizing them in a self-configuring Peer to Peer system; in this way it is possible to reduce the overall system and operational costs. Our claims are supported by an experimental study based on both simulations and theoretical models that analyze the trade-off between the number of servers and home devices in order to guarantee a service within QoS constraints. Experiments are carried out on a realistic model that abstracts the lookup procedures within the NGN of a big telco provider (i.e., finding the IP address of a given unique user profile).     

ESB技术在高校科研管理系统中的应用研究

对SOA,WebServices和ESB相关核心技术进行了研究,提出了一种基于SOA的ESB技术在企业应用集成中的方案,使企业应用服务易于集成并且提高可重用。根据SOA技术特点和ESB的基本功能要求,对该方案进行了设计,并在高校科研管理系统中进行了应用。验证了其可行性,同时也说明运用该方案可以提高软件的开发效率和软件质量。     

基于SigComp的会话初始化协议压缩算法

独立媒体服务(IMS)是第三代合作伙伴计划(3GPP)在版本5中提出的支持IP多媒体业务的子系统,而基于文本的SIP消息过大成为其在IMS无线环境应用下的瓶颈,因此采用会话初始化协议（SIP）来建立和维护多媒体会话。在SigComp框架下,将改进后的LZSS算法与算术编码相结合对SIP信令进行压缩。实验表明新的算法有较高的压缩率,对改善IMS的SIP会话建立延时有一定的参考价值。     

下一代网络业务管理服务器

下一代网络(NGN)中,业务管理服务器是业务支撑环境的核心组件之一。目前业务管理服务器的系统结构和运行机制无法满足NGN业务开放的需求,该文基于开放体系架构和构件技术提出了业务管理服务器的开放体系结构SMSOA,采用层次化构件设计,同时增加业务管理级别控制中心,基于策略解决多业务管理级别控制问题,提出了有效方法保证业务管理执行的可靠性。     

Toward the automation of a QoS-driven SLA establishment in the Cloud

Composite software as a service (SaaS)-based SOA offers opportunities for enterprises to offer value-added services. The cornerstone for such a business is service level agreements between Cloud customers and Cloud providers. In spite of the hype surrounding composite SaaS, standardized methods that enable a reliable management of service level agreements starting from the SLA derivation from the customer requirements to the SLA establishment between the two stockholders are still missing. To overcome such a drawback, we propose a method for SLA establishment guided by QoS for composite SaaS. Our method provides: (1) a requirement specification language for the Cloud customer to define the composition schemas of the requested services along with its QoS constraints; (2) a Cloud provider offer specification language and method to help in identifying the services and resources that satisfy the customer requirements; and (3) an SLA document definition language and method to specify a deployable composite SaaS on the Cloud. Our approach for SLA establishment embraces model-driven architecture principles to automate the SLA document generation from the customer requirements document. The automation is handled through model transformations along with enrichment algorithms to ensure the generation of complete SLA documents.