UMTS网络的规划和设计（二）

5UMTS业务类和业务质量运营者为用户提供的业务的质量是用户区分运营者优劣的一个因素。从用户角度看,UMTS网络就是该网络能为他们提供什么样的端到端的业务以及这些业务的质量。UMTS网络中对于不同业务的QoS的描述基于UMTS的网络结构,进一步讲,UMTS的QoS结构(见图     

分级支持QoS的3G UMTS无线接入网IP/MPLS传输模型

对实现UMTS系统端到端QoS过程中UTRAN所面临的挑战及可能采用的QoS技术进行了分析，然后结合3GPP UMTS业务规范，提出了一种在UTRAN中基于DiffServ机制分级支持QoS的IP／MPLS传输模型。     

基于UMTS的P0C业务QoS研究

文章首先介绍了UMTS系统端到端的QoS架构及业务的QoS等级分类，然后重点分析了基于UMTS系统的PoC业务的端到端QoS保证问题，最后针对PoC业务无线链路传输的时延问题提出了一种降低时延的方法，仿真表明：对于支持IP包压缩的网络来说，该方法可有效优化PoC业务用户体验。     

UMTS对分组数据业务的QoS保证

文章详细分析了UMTS（通用移动通信系统）的端到端QoS体系架构、QoS相关参数和属性以及对分组数据的处理，并讨论了分组数据在UMTS中的QoS实现问题，最后得出结论：通常情况下UMTS可以较好地保证多媒体业务的端到端QoS。     

EV-DO系统支持差异化服务的QoS应用研究

EV-DO系统是专门针对移动多媒体应用进行优化的无线传输技术.本文概述了EV-DO Rev A系统的QoS机制及端到端QoD体系架构,分析了EV-DO系统为不同用户、不同业务提供差异化服务的QoS需求,探讨了EV-DO系统支持差异化服务的端到端QoS技术及应用,并指出了进一步改进分组调度算法和速率控制技术以优化无线资源管理,从而满足用户公平性、不同用户和业务的QoS要求.     

基于UMTS的PoC业务QoS研究

文章首先介绍了UMTS系统端到端的QoS架构及业务的QoS等级分类,然后重点分析了基于UMTS系统的PoC业务的端到端QS保证问题,最后针对PoC业务无线链路传输的时延问题提出了一种降低时延的方法,仿真表明:对于支持IP包压缩的网络来说,该方法可有效优化PoC业务用户体验.     

UMTS中实现端到端QoS技术的研究

本文从Internet的QoS角度出发，着重分析了UMTS内的QoS技术和实现UMTS端到端QoS所需要的关键技术。     

3G UMTS对分组数据业务的QoS保证

文章详细分析了UMTS（通用移动通信系统）的端到端QoS体系架构、QoS相关参数和属性以及对分组数据的处理,并讨论了分组数据在UMTS中的QoS实现问题,最后得出结论：通常情况下UMTS可以较好地保证多媒体业务的端到端QoS。     

MTS对分组数据业务的QoS保证

文章详细分析了UMTS（通用移动通信系统）的端到端QoS体系架构、QoS相关参数和属性以及对分组数据的处理,并讨论了分组数据在UMTS中的QoS实现问题,最后得出结论：通常情况下UMTS可以较好地保证多媒体业务的端到端QoS。     

3G中的QoS结构及无线资源分配策略

在3G（第3代移动通信系统）中，为了给不同类型的业务提供不同级别的端到端QoS，网络资源必须进行合理分配。QoS和资源分配是密不可分的，而无线资源分配显得尤为重要。文中提出了UMTS的QoS结构，分3部分对空中接口部分的QoS（即无线资源分配策略问题）进行了讨论：首先提出了一种RRA算法，接着讨论了W－CDMA和TD－CDMA系统的无线资源分配问题，最后讨论了下行链路及上行链路的呼叫允许控制（CAC）。     

Policy-based QoS architecture in the IP multimedia subsystem of UMTS

The third-generation mobile system, or Universal Mobile Telecommunication System, will offer IP-based multimedia applications and services with end-to-end QoS guarantee. The key part providing these services is the policy-based QoS control architecture in the IP multimedia subsystem (IMS). In this tutorial we describe the network entities involved in the policy-based QoS architecture, their interactions to realize guaranteed QoS in the UMTS network, and the communication interfaces employed in the interactions.     

Scalable Quasi‐Dynamic‐Provisioning‐Based Admission Control Mechanism in Differentiated Service Networks

The architecture in a differentiated services (DiffServ) network is based on a simple model that applies a per‐class service in the core node of the network. However, because the network behavior is simple, the network structure and provisioning is complicated. If a service provider wants dynamic provisioning or a better bandwidth guarantee, the differentiated services network must use a signaling protocol with QoS parameters or an admission control method. Unfortunately, these methods increase the complexity. To overcome the problems with complexity, we investigated scalable dynamic provisioning for admission control in DiffServ networks. We propose a new scalable qDPM² mechanism based on a centralized bandwidth broker and distributed measurement‐based admission control and movable boundary bandwidth management to support heterogeneous QoS requirements in DiffServ networks.     

A Study on Differentiated Service Queuing Scheme with an Overflow Buffer Allocation Within a UMTS Core Network

According to the QoS features of the four types of UMTS traffic, this study proposes a priority-based queuing scheme to support differentiated services among all UMTS traffic; it bases on packet transmission priorities of four types of UMTS traffic to handle packets forwarding in a gateway within a UMTS core network. In the proposed queuing scheme, a static dedicated logical queuing buffer allocation and a dynamic overflow buffer allocation are used to support packet enqueuing/dequeuing jobs. In this study, the ns2 network simulator is used as a simulation platform and different categories of simulation scenarios are executed. Moreover, the IETF DiffServ scheme is used as a comparison to understand the packet forwarding performance of the proposed scheme. By analyzing simulation data, two important points can be drawn. The proposed queuing scheme supports a differentiated packet forwarding behavior among four types of UMTS traffic. And, the differentiated packet forwarding behaviors with the proposed queuing scheme are similar to the packet forwarding behavior with the IETF DiffServ scheme.     

基于区分服务的边缘路由器的服务质量

Internet real-time multimedia communication brings a further challenge to Quality of Service （QoS）. A higher QoS in communication is required increasingly. As a new framework for providing QoS services, Differentiated Services （DiffServ） is undergoing a speedily standardization process at the IETF. DiffServ not only can offer classified level of services, but also can provide guaranteed QoS in a certain extent. In order to provide QoS, DiffServ must be properly configured. The traditional DiffServ mechanism provides classifier for edge router to mark the different traffic streams, and then the core router uses different Drop Packet Mechanisms to drop packets or transmit data packets according to these classified markers. When multiple edge routers or other core routers transmit data packets high speedily to a single core router, the core router will emerge bottleneck bandwidth. The most valid solution to this problem is that the edge router adopts drop packet mechanism. This paper proposes an Modified Edge Router Mechanism that let the edge router achieve marking, dropping and transmitting packets of hybrid traffic streams based on DiffServ in a given bandwidth, the core router will only transmits packets but won＇t drop packets. By the simulation of ns2, the modified mechanism ensure the QoS of high priority traffics and simplify the core router, it is a valid method to solve the congestion of the core router.     

DiffServ resource allocation for fast handoff in wireless mobileInternet

The next-generation wireless networks are evolving toward a versatile IP-based network that can provide various real-time multimedia services to mobile users. Two major challenges in establishing such a wireless mobile Internet are support of fast handoff and provision of quality of service (QoS) over IP-based wireless access networks. In this article, a DiffServ resource allocation architecture is proposed for the evolving wireless mobile Internet. The registration-domain-based scheme supports fast handoff by significantly reducing mobility management signaling. The registration domain is integrated with the DiffServ mechanism and provisions QoS guarantee for each service class by domain-based admission control. Furthermore, an adaptive assured service is presented for the stream class of traffic, where resource allocation is adjusted according to the network condition in order to minimize handoff call dropping and new call blocking probabilities     

Multi-domain architecture for policy management inumts ip multimedia subsystem

The Universal Mobile Telecommunications System (UMTS) offers IP-based multimedia applications and services with end-to-end Quality of Service (QoS) guarantee. The key component providing these services is the IP Multimedia Subsystem (IMS) that uses Service-Based Local Policy (SBLP) management for QoS control. To support end-to-end QoS, the UMTS IMS network should be scalable, reliable and flexible in policy deployment and enforcement, characteristics that are not found in single-domain policy architecture. A hybrid policy architecture is proposed, in which a hierarchical architecture is applied to the multi-domain environment in a single operator UMTS IMS network, while a peering architecture is employed in a multi-operator UMTS IMS network. The proposed multi-domain policy architecture potentially minimizes the session setup delay and policy exchange traffic while maximizing network scalability.     

基于区分服务的IP-UMTS视频传输QoS机制

为了满足在以IP作为骨干网协议,以通用移动通信系统(UMTS)作为接入网的异构网络环境中视频传输的服务质量要求.提出了基于区分服务的视频传输服务质量机制,给出了区分服务业务等级到视频数据帧和区分服务业务等级到UMTS业务类别的映射关系.使用仿真的实验环境对给定的服务质量机制进行了测试,实验结果表明该服务质量机制能有效地提高IP-UMTS异构网络中视频传输的服务质量.     

基于DiffServ的IMS QoS保障机制研究

服务质量（QoS）是下一代网络（NGN）的关键问题，IMS作为3GPP提出的下一代网络的核心架构，需要提供可靠的QoS保障。文章提出了IMS中QoS的解决方案，并针对IMS网络层进行深入研究。通过区分业务（DiffServ）技术来提供网络层QoS支持，并对几种实现DiffServ模型的分组调度算法进行了探讨。     

A flexible and distributed architecture for adaptive end-to-end QoS provisioning in next-generation networks

A novel distributed end-to-end quality-of-service (QoS) provisioning architecture based on the concept of decoupling the end-to-end QoS provisioning from the service provisioning at routers in the differentiated service (DiffServ) network is proposed. The main objective of this architecture is to enhance the QoS granularity and flexibility offered in the DiffServ network model and improve both the network resource utilization and user benefits. The proposed architecture consists of a new endpoint admission control referred to as explicit endpoint admission control at the user side, the service vector which allows a data flow to choose different services at different routers along its data path, and a packet marking architecture and algorithm at the router side. The achievable performance of the proposed approach is studied, and the corresponding results demonstrate that the proposed mechanism can have better service differentiation capability and lower request dropping probability than the integrated service over DiffServ schemes. Furthermore, it is shown that it preserves a friendly networking environment for conventional transmission control protocol flows and maintains the simplicity feature of the DiffServ network model.