A dynamic quality of service framework for video in broadbandnetworks

A dynamic framework for QoS control of video in distributed multimedia applications is presented. The framework allows flexible and efficient video delivery with application-level QoS support. Key components of the framework are client QoS renegotiation, server source rate control, and dynamic bandwidth allocation. The coordinated functionality of these distributed components provides soft QoS to adaptive applications. A proof-of-concept prototype of a video browser with user-level control of soft QoS is implemented within the proposed framework. The implementation uses a distributed software architecture that represents soft QoS requirements by software objects called service contracts. These objects are exchanged among servers, network nodes, and clients to achieve distributed soft QoS control. Experiences with the prototype and its performance are discussed     

Quality-of-service architecture: Monitoring and control ofmultimedia communications

For distributed multimedia applications the provision of system-wide quality of service (QoS) is essential. The quality-of-service architecture (QoS-A) developed at Lancaster University offers a framework to specify and implement the required performance properties of multimedia applications over integrated-service networks in a heterogeneous environment. The work addresses the problem of lower-level QoS as well as QoS support for multipeer multimedia applications operating in an open communication system. QoS filters have been developed to deal with the problems of heterogeneity in group communication environments. New challenges are also encountered in emerging mobile networks and user mobility; and recent developments in the Internet community highlight the need for appropriate QoS support mechanisms for multimedia applications. The paper describes how the QoS-A research at Lancaster University provides a flexible framework for the monitoring and control of multimedia communications across the broad range of computing systems and networks     

End-to-end QoS resource management for an IP-based DWDM access network

The ever-increasing use of broad-band Internet and complex multimedia applications is pushing fiber closer and closer to the homes. Within the European project IST HARMONICS (Hybrid Access Reconfigurable Multi-wavelength Optical Networks for IP-based Communication Services), an optical access feeder network and resource management framework were developed that tackle this demand for bandwidth and the desire to stimulate the convergence of last-mile access technologies. To cope with the lack of bandwidth in the access and last-mile networks and the different needs of applications and users, the developed management system provides end-to-end quality of service (QoS) while integrating multiple technologies. In this paper, a detailed overview of the end-to-end QoS management framework and novel time slot/wavelength MAC protocol for the optical feeder network is given. End-to-end QoS is based on Differentiated services (DiffServ) at layer 3, various QoS supporting technologies at layer 2, and QoS mappings between both layers. The paper will also focus on the field trial results of the HARMONICS project and give some guidelines for possible problems and solutions in this area.     

Principles of QoS in group communications

In this paper, we consider QoS support in the context of group communications. In particular, we present fundamental properties of QoS in group communications, which, although quite simple, have been widely overlooked and/or misunderstood. Because distributed multimedia applications require flexible QoS agreements, end-to-end QoS negotiation will play an important role. We show how such a negotiation mechanism can be designed, taking the fundamental QoS properties into account. This leads us to the design of an algorithm for QoS negotiation whose computational overhead proves to be independent of the size of the group of receivers.     

Quality of service in telecommunications. I. Proposition of a QoSframework and its application to B-ISDN

The the quality of service (QoS) concept is becoming an ever more important issue in telecommunication and computer communication. The article focuses on the QoS notion and concept. The definition of QoS in the International Telecommunications Union-Telecommunications Sector (ITU-T) recommendations and the International Standards Organization (ISO) standards is analysed. Little is known about the asynchronous transfer mode (ATM) performance requirements of the broadband integrated services digital network (B-ISDN) services, especially for multimedia applications. This is because the ATM performance requirements of multimedia applications depend not only on the diverse QoS requirements from application and user, but also on the protocol stacks and scheduling in end systems. Therefore, in order to guarantee QoS to the user, it is necessary to introduce a set of QoS parameters whose properties indicate the nature and requirements of the layered protocol stack. We describe how a proposed QoS framework can be applied to B-ISDN as a specific network. The QoS aspects related to B-ISDN signaling (the control plane) and the QoS aspects related to layer and plane management (the management plane) are described. We also describe how the QoS framework resides in a protocol stack and works together with the B-ISDN network management and signaling     

Distributed Busacker–Gowen algorithm for end-to-end QoS pipe negotiation in X-domain networks

Multimedia services and other critical multisite services (e.g., VPN) are becoming mainstream, and they require a guaranteed quality of service (QoS). Services need to be established across several autonomous systems (ASes), often to connect end-users. Thus, provisioning and control of end-to-end QoS requirements arise as one of the main challenges in inter-AS management. The contractual approach, consisting in using service-level agreements (SLAs) defined by each crossed AS, allows to negotiate contract chains that satisfy end-to-end requirements. However, establishing such chains by on-demand negotiations does not scale up for large numbers of requests. Hence, we propose a negotiation process to occur before users’ requests to establish service are received. The proposed negotiation process results in the selection of aggregated contract chains, called pipes, and a distribution between them. Such a distribution would indicate, for each chain of a pipe, the connection flow it may accept. In this paper, we address the pipe negotiation problem as a network flow problem. We also propose a distributed adaptation of an algorithm for network flow problems.     

Adaptively controlling the QoS of multimedia wireless applications through "user profiling" techniques

A large amount of research is currently focusing on the issue of the adaptive control of the quality-of-service (QoS) provided to multimedia applications in heterogeneous wireless systems. In this paper, the authors aim at contributing to this issue by proposing a mechanism that exploits user profiling techniques and suitable QoS mapping functions to introduce the soft QoS idea into a wireless multimedia scenario. The research objective is a QoS control architecture, which enables the continuous convergence between the actual user preferences and expectations and the resource constraints of the underlying wireless system. The proposed architecture operates between the system and the application layer. This allows it to achieve the intended results, by means of an effective dynamic reconfiguration of the applications and the contemporary renegotiation of the wireless resources.     

Design of a Link Control Protocol for Multimedia Services in Wireless Local Communication

The convergence of wireless systems with multimedia services is the challengeof future generation wireless networks. The large variety of QoS requirementsof different media as well as the maintenance of synchronization of thedifferent streams to be presented at receiver, demand from the Data link layersome extra functionalities. In this paper, we present an enhanced approach forthe efficient management of multimedia applications in third-generationwireless networks. We advocate the use of multiple connections, one for eachtraffic component of the application, as the effective solution for thetransport of multimedia applications in future-generation wireless networks.The effectiveness of this scheme is guaranteed by providing a new link controltechnique that works on top of a PRMA-type access protocol which jointlymanages different streams of a multimedia application. For this purpose, wepropose a two-level priority mechanism (static and dynamic priorities)specified by higher protocol layers for link activation, channel access, andadmission control procedures specific to a multimedia application and foroptimizing the sharing of radio channel resources and management of thereservation queue at the base station. We expect this priority-based mechanismto perform well, especially during periods in which system traffic load ishigh, and to react well to the deterioration of multimedia service quality,in terms of both QoS parameters and the synchronization of its trafficcomponents.     

Distributed resource allocation for DS-CDMA-based multimedia ad hocwireless LANs

Power control in direct sequence code division multiple access (DS-CDMA) systems and power/rate allocation in multirate DS-CDMA based networks is an open and interesting research area which has attracted much attention. However, with a few exceptions, most researchers have emphasized centralized resource allocation algorithms for cellular systems where the base station keeps track of the requirements of the various users and is thus responsible for the management of network resources. Ad hoc wireless local area networks (WLANs), on the other hand, are generally configured as peer-to-peer networks with no centralized hub or controller. Thus resource allocation has to be conducted in a distributed fashion. We address the issue of distributed resource management for multirate DS-CDMA based multimedia WLANs by (1) presenting a distributed resource allocation protocol, known as distributed resource negotiation protocol (DRNP) that builds on the RTS/CTS bandwidth reservation mechanism provided by IEEE 802.111, and provides quality of service (QoS) guarantees through distributed control of resources in DS-CDMA based multimedia WLANs and (2) investigating the performance of various resource allocation schemes within the context of DRNP, in terms of network wide metrics such as overall throughput and blocking rates     

Admission control in time-slotted multihop mobile networks

The emergence of nomadic applications have generated a lot of interest in next-generation wireless network infrastructures which provide differentiated service classes. So it is important to study how the quality of service (QoS), such as packet loss and bandwidth, should be guaranteed. To accomplish this, we develop am admission control scheme which can guarantee bandwidth for real-time applications in multihop mobile networks. In our scheme, a host need not discover and maintain any information of the network resources status on the routes to another host until a connection request is generated for the communication between the two hosts, unless the former host is offering its services as an intermediate forwarding station to maintain connectivity between two other hosts. This bandwidth guarantee feature is important for a mobile network to interconnect wired networks with QoS support. Our connection admission control scheme can also work in a stand-alone mobile ad hoc network for real-time applications. This control scheme contains end-to-end bandwidth calculation and bandwidth allocation. Under such a scheme, the source is informed of the bandwidth and QoS available to any destination in the mobile network. This knowledge enables the establishment of QoS connections within the mobile network and the efficient support of real time applications. In the case of ATM interconnection, the bandwidth information can be used to carry out an intelligent handoff between ATM gateways and/or to extend the ATM virtual circuit service to the mobile network with possible renegotiation of QoS parameters at the gateway. We examine via simulation the system performance in various QoS traffic flows and mobility environments     

Multimedia communication

Multimedia communication deals with the transfer, protocols, services, and mechanisms of discrete media data (such as text and graphics) and continuous media data (like audio and video) in/over digital networks. Such a communication requires all involved components to be capable of handling a well-defined quality of service (QoS). The most important QoS parameters are used to request: (1) the required capacities of the involved resources, (2) compliance to end-to-end delay and jitter as timing restrictions, and (3) restriction of the loss characteristics. In this paper, we describe the necessary issues and study the ability of current networks and communication systems to support distributed multimedia applications. Further, we discuss upcoming approaches and systems that promise to provide the necessary mechanisms and consider which issues are missing for a complete multimedia communication infrastructure     

QoS management in mobile IP networks using a terminal assistant

This paper describes a signalling environment for Quality of Service (QoS) negotiation and advance resource reservation in mobile IP networks. This environment is built in conformance with the generic signalling environment, which is standardized by the NSIS IETF working group. The advanced resource reservation protocol, called MQoS NSLP, is based on the QoS NSLP signalling application. It provides to mobile terminals the QoS required based on the user's mobility and QoS profile. In this work, we investigate the use of some techniques of the AI (Artificial Intelligence) domain to implement a user interface called NIA (Negotiation Individual Assistant) in order to determine the QoS profile and negotiate the QoS parameters in the new domain after the handover. Therefore, we use connectionist learning in the management of the negotiation profiles and agent technology to help the user choose the best service provider, dynamically negotiate the QoS on the user's behalf, and follow the user's behaviour to be able to anticipate the negotiation and manage renegotiation. The advance resource reservation is based on an object MSpec (Mobility Specification) which determines the future location of the mobile terminal. The MSpec object is a part of the mobility and QoS profile and is determined by the NIA in the mobile terminal. Copyright © 2008 John Wiley & Sons, Ltd.     

Application-Level QoS Negotiation and Signaling for Advanced Multimedia Services in the IMS

The IP multimedia subsystem (IMS) has been recognized as a reference next-generation network architecture for offering multimedia services over an Internet Protocol (IP)-based infrastructure. One of the key benefits of the IMS is efficient and flexible introduction of new services and access to third-party application providers, thanks to standard interfaces and standardized service capabilities. To support novel media-rich applications across a wide range of user devices and access networks, IMS must support negotiable quality of service (QoS) for IP multimedia sessions. In this article, we describe the application-level QoS signaling as specified by the 3GPP and propose some enhancements based on advanced QoS parameter matching and optimization functionality to be included along the signaling path. We outline various signaling flow scenarios and discuss them in the context of a case study involving an IMS-supported 3D virtual environment, featuring a treasure-hunt-like game.     

QoS specification languages for distributed multimedia applications: a survey and taxonomy

Following considerable research into quality-of-service-aware application programming interface design and QoS specification language development for multimedia systems, we present a survey and taxonomy of existing QoS specification languages. As computer and communication technology evolves, distributed multimedia applications are becoming ubiquitous, and quality of service (QoS) is becoming ever more integral to those applications. Because they consume so many resources (such as memory and bandwidth), multimedia applications need resource management at different layers of the communications protocol stack to ensure end-to-end service quality, and to regulate resource contention for equitable resource sharing. However, before an application can invoke any QoS-aware resource management mechanisms and policies - such as admission control, resource reservation, enforcement, and adaptation - it must specify its QoS requirements and the corresponding resource allocations. Furthermore, the application must describe how QoS should be scaled and adapted in cases of resource contention or resource scarcity during runtime. Our goal in this article is to systematically classify and compare the existing QoS specification languages that span several QoS layers with diverse properties. The provided taxonomy and the extensive analysis will give us a detailed look at the existing QoS specification languages along with their properties and relations.     

End-to-end service level negotiation protocol for self-management networks

We propose a framework for service level negotiation within s elf-management systems. The negotiation process occurs between high-level autonomic managers to guarantee an end-to-end service level for specific application traffic flows. In the proposed framework, we provide autonomic systems with a new interaction opportunity thanks to the negotiation with their peers. To be in conformance with the concepts of self-aware management systems, the proposed negotiation protocol called SLNP is used in a Web Services environment.     

Radio resource management with QoS guarantees for LTE-A systems: a review focused on employing the multi-objective optimization techniques

The increasing number of subscribers’ demand has led to the evolution of future wireless networks that support multimedia applications and require ensuring the quality of services it provides. As the radio resource is becoming scarce, it is turning out to be a vital issue that how should the demands for higher data rates with limited resources is met for the evolving long term evolution-advanced (LTE-A) systems. Moreover, the efficiency and performance of resource management can be further improved by autonomously assigning and managing resources among various users and applications. We have surveyed various radio resource management (RRM) techniques being used for resource sharing in LTE-A networks that focus on the potential of multi-objective optimization algorithms for achieving desired QoS in LTE-A system. In this paper, we present a comprehensive review of RRM techniques, scheduling, and QoS along with a focus on implementing the multi-objective optimization techniques for efficient resource allocation.     

Design and performance evaluation of active bandwidth brokers

With the arrivals of critical data transactions and multimedia applications, the needs of network services with different Quality of Service (QoS) guarantees increase rapidly. In order to ensure the delivery of information with a desired quality at the application layer, policy-based management (pbm) systems should be deployed at network service providers for configuring network devices properly. A policy-based management system is capable of resolving and enforcing policy rules in realizing end-to-end QoS for all kinds of network connections. In this paper, a novel design of policy-based management system based on active networks is proposed. Active network technology empowers network routers the ability to execute and move data and program code as needed. It is used in the proposed design (Active Bandwidth Broker architecture) to achieve the goals of system scalability and reliability. Moreover, policy control operations can be distributed among different active nodes. Thus, the architecture reduces the aggregate amount of policy control traffic in networks and expedites the response times on policy requests. Furthermore, the Policy Decision Point is a mobile agent that moves and avoids encountering network congestion situations. A system prototype has been constructed to implement the designed architecture. It has successfully demonstrated that the new design framework offers architecture flexibility, improves system reliability, and provides system scalability in handling a large number of service requests.     

COPS-SLS usage for dynamic policy-based QoS management over heterogeneous IP networks

While each IP domain can deploy its own strategy to manage network resources, multimedia traffic needs end-to-end QoS management to obtain an overall service level. The provision of end-to-end QoS over a heterogeneous environment implies the negotiation of a mutually acceptable SLA. This article presents the use of the COPS-SLS protocol as a generic protocol for automatic service-level negotiation and the integration of this protocol in an overall QoS management architecture to manage service levels over multiple domains deploying different QoS technologies.     

Evolution of the Internet QoS and support for soft real-time applications

The past few years have witnessed the emergence of many real-time networked applications on the Internet. These types of applications require special support from the underlying network such as reliability, timeliness, and guaranteed delivery, as well as different levels of service quality. Unfortunately, this support is not available within the current "best-effort" Internet architecture. In this paper, we review several mechanisms and frameworks proposed to provide network- and application-level quality of service (QoS) in the next-generation Internet. We first discuss the QoS requirements of many of the above-mentioned real-time applications, and then we categorize them according to the required service levels. We also describe the various building blocks often used in QoS approaches. We briefly present asynchronous transfer mode (ATM) and Internet Protocol precedence. Then, we present and compare two service architectures recently adopted by the Internet Engineering Task Force, called integrated services (IntServ) and differentiated services (DiffServ), for providing per-flow and aggregated-flow service guarantees, respectively. We focus on DiffServ because it is a candidate QoS framework to be used in next-generation Internet along with multiprotocol label switching and traffic engineering. We also examine several operational and research issues that need to be resolved before such frameworks can be put in practice.     

CDMA EVDO网络中的QoS保障机制研究

随着3G无线分组网络的飞速发展,基于移动终端的实时多媒体业务需求也日趋广泛.如何保障诸如流媒体直播和可视通话等QoS要求较高的业务,必将成为一个重要的课题.对CDMA EVDO网络中的QoS保障机制进行了初步探讨,阐述了CDMA EVDO网络的QoS实现架构,并以终端MS源发呼叫的QoS协商过程为例,描述了其信令流程.