Extending next generation network (NGN) architecture for connection-oriented transport

Next Generation Network (NGN) is the architecture of the International Telecommunication Union-Telecommunication Standardization Sector (ITU-T in short) supporting the provisioning of Quality of Service (QoS)-guaranteed services over different packet transport technologies. Such capability derives from the effectiveness of a dynamic resource control performed by the Resource Admission Control Function (RACF) at service set-up.Control Plane (CP)-enabled connection-oriented transport networks can guarantee the QoS support for new bandwidth-greedy NGN services across the optical transport segment thanks to the ability of automatic path set-up and traffic segregation. But the Internet Engineering Task Force (IETF) standard for the CP in transport networks, i.e., the Generalized Multi-Protocol Label Switching (GMPLS) is not yet included within the NGN supported transport technologies.In this work, we outline architectural guidelines and design strategies for ITU-T RACF employment across GMPLS-controlled networks while providing a viable solution for dynamic resource control that takes into account operational issues for the integration of GMPLS capabilities within NGN architecture (i.e., supported interfaces, actual node capabilities).An NGN prototype implementing the proposed architectural enhancement is also presented as a proof of concept. The prototype highlights how the extended ITU-T NGN can set-up Multimedia over IP (MoIP) services using GMPLS-controlled transport objects.     

Dynamic resource control mechanism for multimedia overlay transport in NGN

This paper investigates a dynamic resource control mechanism to efficiently deliver NGN multimedia services while supporting quality of service (QoS) requirements and bandwidth flexibility in next generation networks (NGN). The proposed resource control aims to realize the dynamic and automatic setup and release of multimedia resource sessions across heterogeneous transport networks including IP, SONET/SDH, and WDM technologies. It can also provide not only low cost operations but also flexibility for multimedia resource control.     

From IMS Management to SOA Based NGN Management

Although IP Multimedia Subsystem (IMS) based Next Generation Networks (NGNs) are already emerging as the common session control platform for converging fixed, mobile and cable networks, harmonized solutions for the management of these converged platforms have still got to be developed. This document describes a hands-on approach to NGN Management. Started with IMS specific management systems, succeeding research had to take into account the importance of the management of NGN SDPs as well. This work shows that the hybrid nature of an NGN, where services can be delivered at the IMS layer, by SIP signaling mechanisms, as well as at the SDP, via Web Services, requires a harmonized management approach. Taking into account Service Oriented Architecture (SOA) principles and policy based model driven architectures, this work shows that a unification of service composition and service management already at the workflow creation level, bares significant benefits in terms of automation and harmonization. Following the SOA paradigm, the approach presented here does not differentiate between business process management (BPM) and management process management. Focusing on Telemanagement Forum’s enhanced Telecom Operations Map service fulfillment and service assurance operations, this document describes an New Generation Software and Services (NGOSS) based implementation of a unified Operation Support System (OSS) for NGNs that encompasses many problems of former stovepipe management solutions in terms of automation, flexibility and manageability.     

Admission control with elastic QoS for video on demand systems

In network service systems, satisfying quality of service (QoS) is one of the main objectives. Admission control and resource allocation strategy can be used to guarantee the QoS requirement. Based on partially observable Markov decision processes (POMDPs), this paper proposes a novel admission control model for video on demand (VOD) service systems with elastic QoS. Elastic QoS is also considered in resource allocation strategy. Policy gradient algorithm is often available to find the solution of POMDP problems, with a satisfactory convergence rate. Through numerical examples, it can be shown that the proposed admission control strategy has better performance than complete admission control strategy.     

分布式视频点播系统的接入控制研究

Video on Demand(VoD)systems are considered as one of the most valuable services for the next generation broad-bandwidth Internet. To provide high-quality service, the VoD system must employ an admission control module to guarantee QoS, but there are still less research works having been made in this field, especially for distributed VoD systems. In this paper, we mainly focus on distributed admission control for VBR video streams in distributed VoD systems. We firstly discuss different approaches and then two admission control strategies are proposed with experimental comparisons. Our research is also further extended to resource assignment in distributed VoD systems. At the end of this article, we address issues in implementing distributed admission control.     

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.

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.

IMS 中基于策略QoS 管理模型

IMS（IP多媒体子系统）给客户带来丰富的多媒体体验的同时,也对服务质量（QoS）管理提出了更高的要求,即针对不同用户定制的不同服务,网络运营商应该制定差异化的策略进行QoS管理。3GPP定义了基于策略的QoS管理框架,但这个框架只是逻辑上的架构,没有定义具体物理实施的方案。对基于策略QoS管理模型进行了分析,在参照3GPP定义的标准基础上,提出了一种管理模型的实现方案,设计并实现了该模型中两个关键服务器策略决策服务器（PDF）和策略执行服务器（PEP）。经过测试,两个服务器能互相配合,正确完成查询策略信息,做出策略决策,执行带宽请求预留、QoS等级协商功能,为网络运营商提供了参考。     

Third party application control on quality of service in IP based multimedia networks

The paper investigates the capabilities for open access to resource management in convergent networks. Based on the analysis of policy and charging control functions in Internet Protocol Multimedia Subsystem (IMS), requirements for third party application control on quality of service (QoS) are identified. The functionality of Open Service Access (OSA) and Parlay X interfaces is evaluated for support of dynamic QoS control. An approach to design of OSA compliant application programming interfaces to QoS management in IMS networks is presented. The interface methods are mapped onto the messages of network control protocols such as Diameter and Session Initiation Protocol (SIP). The application view of authorized QoS resources for SIP session is modeled. Implementation issues concerning behavioral equivalence of the authorized QoS resources model and SIP session state model are discussed.     

基于MDP支持弹性服务质量的接入控制

在网络服务系统中,满足业务请求的服务质量需求是系统要解决的主要问题之一。接入控制方法和资源分配策略常用来保证业务的服务质量要求。本文基于Markov决策过程(MDP)对视频点播(VOD)系统进行建模,同时考虑了弹性服务质量这一机制。弹性服务质量可以用一个QoS的需求范围来体现。策略梯度算法常用来解决MDP问题,它能够以比较好的速度收敛到最优解。通过算法实例对本文的接入控制方法进行性能分析,发现所采用的方法相对于一般的完全接入策略具有较优的性能。     

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     

QoS-Aware Admission Control and Dynamic Resource Provisioning Framework in Ubiquitous Multimedia Computing Environments

A ubiquitous service deployment is emerging in the multimedia, networking, and wireless mobile computing area. Therefore, there has been an increasing demand for ubiquitous computing environments to support a certain degree of quality of service (QoS) to meet various service requirements from different computing and networking applications, and to better utilize the computing resources. However, supporting QoS in the ubiquitous computing environments has also raised great concerns regarding the applicability of any QoS solution. Management of such ubiquitous multimedia applications requires new mechanisms, i.e., Soft-QoS framework, to be developed for admission control, negotiation, allocation, and scheduling. In this paper, we present a novel negotiated admission control algorithm that exploits the degradability property of applications to improve the performance of the system. The algorithm is based on setting aside a portion of the resources as reserves and managing it intelligently, so that the total utility of the system can be maximized. The mixed greedy and predictive strategy leads to an efficient protocol that also improves the system performance. We use the constructs of application benefit functions and resource demand functions in the integrated admission control and negotiation protocol. We applied our Soft-QoS framework to the admission controlling and resource scheduling for ubiquitous multimedia devices such as Continuous Media (CM) or Video-On-Demand (VOD) servers, where multimedia applications can generally tolerate certain variations on QoS parameters by providing multiple classes with consistently proportional rather than absolute QoS. Extensive simulation experiments are presented in the paper to evaluate the performance of the novel mechanisms and compare it against some other methods used in the past.This work was in part funded by DARPA through the SPAWARSYSCEN under Contract Number N66001-97-C-8525 and SK Telecom, Korea, under Contract Number (KU-R0405721).     

SLA-controlled interconnection charging in next generation networks

Next generation network (NGN) should facilitate a single party to establish quality of service (QoS) enabled path between the two IP providers mutually interconnected by one or more transit providers. For that purpose, an end-to-end service level agreement (SLA) should be negotiated and maintained. In this article, we propose interconnection charging, which is controlled by the end-to-end SLA. Relationships between the required, offered, and actually achieved inter-provider QoS are quantified through the degrees of offering and provisioning, at both end-to-end and per-domain levels. Nominal retail price offered to end users and interconnection costs related with particular SLA are then corrected if needed, depending on the offered and provisioned QoS levels. We further propose five policies for interconnection charging and compare them under different QoS provisioning scenarios. Results of the analysis indicate that a properly selected SLA-controlled interconnection charging policy should encourage providers: (1) to offer services with different QoS levels; (2) to offer service that perfectly or most approximately matches the required QoS and (3) to achieve the contracted QoS level.     

Scheduling and flexible control of bandwidth and in-transit services for end-to-end application workflows

End-to-end scientific application workflows that integrate high-end experiments and instruments with large scale simulations and end-user displays are becoming increasingly important. These workflows require complex couplings and data sharing between distributed components involving large data volumes and present varying hard (in-time data delivery) and soft (in-transit processing) quality of service (QoS) requirements. As a result, supporting efficient data transport is critical for such workflows. In this paper, we leverage software-defined networking (SDN) to address issues of data transport service control and resource provisioning to meet varying QoS requirements from multiple coupled workflows sharing the same service medium. Specifically, we present a flexible control and a disciplined resource scheduling approach for data transport services for science networks. Furthermore, we emulate an SDN testbed on top of the FutureGrid virtualized testbed and use it to evaluate our approach for a realistic scientific workflow. Our results show that SDN-based control and resource scheduling based on simple intuitive models can meet the requirements of the targeted workflows with high resource utilization.     

Dynamic radio resource allocation for 3G and beyond mobile wireless networks

Next generation of wireless cellular networks aim at supporting a diverse range of multimedia services to mobile users with guaranteed quality of service (QoS). Resource allocation and call admission control (CAC) are key management functions in future 3G and 4G cellular networks, in order to provide multimedia applications to mobile users with QoS guarantees and efficient resource utilization. There are two main strategies for radio resource allocations in cellular wireless networks known as complete partitioning (CP) and complete sharing (CS). In this paper, theses strategies are extended for operation in 3G and beyond network. First, two CS-based call admission controls, referred to herein as queuing priority call admission control (QP-CAC) and hybrid priority call admission control (HP-CAC), and one CP-based call admission control referred to as complete partitioning call admission control (CP-CAC) are presented. Then, this study proposes a novel dynamic procedure, referred to as the dynamic prioritized uplink call admission control (DP-CAC) designed to overcome the shortcomings of CS and CP-based CACs. Results indicate the superiority of DP-CAC as it is able to achieve a better balance between system utilization, revenue, and quality of service provisioning. CS-based algorithms achieve the best system utilization and revenue at the expense of serious unfairness for the traffic classes with diverse QoS requirements. DP-CAC manages to attain equal system utilization and revenue to CS-based algorithms without the drawbacks in terms of fairness and service differentiation.     

A novel pricing approach to support QoS in 3G networks

Pricing in 3G and other communication networks may control and manage the utilisation of network resources. The available network resources get strained with increased usage levels, which results in poor service to the users. Most users prefer receiving high quality services at affordable costs. This requires the provision of QoS guarantees for network services at a low cost. In a real business scenario, this relationship is hard to achieve; moreover revenue sources for network operators have been shifting from the provision of network access to provisioning of rich services, e.g. multimedia services. To attain a functional compromise, we propose a pricing scheme that relies on service profiles to manage resource utilisation in a DiffServ-enabled 3G network. The service profiles define the QoS achieved for accessing services through a common resource pool, in which resource sharing is used to maximise network resource utilisation, user satisfaction and profits for the network operators. In an NGN scenario users would select pricing profiles according to their budgets, and the network will map these profiles to a set of QoS options that may translate to the choice of an access network for service access. In this paper, we present the mathematical model of the proposed pricing scheme, the proposed design of an evaluation framework, QoS performance results, and a service provisioning scenario illustrating the applicability of the proposed pricing scheme.     

An integrated admission control scheme for the delivery of streaming media

Quality of service (QoS) assurance is a major concern in media-on-demand (MoD) systems. Admission control is one of the most important issues that need to be addressed for QoS assurance. Also, smoothing is a basic technique for the media server to improve its bandwidth and buffer utilization. However, existing approaches cannot achieve the best resource utilization because (1) they cannot fully utilize the time-varying buffer spaces available at both server and client sides due to the separation of admission control and smoothing processes, and (2) the computing time is unacceptable for media of long duration. In this paper, we formulate the admission control as an integer programming problem and propose several heuristic methods for solving the problem. Specially, we introduce an efficient scheme, called batched admission (BA) scheme, which integrates admission control, transmission rate smoothing, and batching, to achieve best resource utilization with guaranteed QoS. Experimental studies show that the BA scheme outperforms existing approaches.     

A survey of QoS architectures

Over the past several years there has been a considerable amount of research within the field of quality-of-service (QoS) support for distributed multimedia systems. To date, most of the work has been within the context of individual architectural layers such as the distributed system platform, operating system, transport subsystem and network layers. Much less progress has been made in addressing the issue of overall end-to-end support for multimedia communications. In recognition of this, a number of research teams have proposed the development of QoS architectures which incorporate QoS-configurable interfaces and QoS driven control and management mechanisms across all architectural layers. This paper examines the state-of-the-art in the development of QoS architectures. The approach taken is to present QoS terminology and a generalized QoS framework for understanding and discussing QoS in the context of distributed multimedia systems. Following this, we evaluate a number of QoS architectures that have emerged in the literature.