QoS Architecture Research Articles

A QoS Architecture for DVB-RCS Next Generation Satellite Networks

The standardization of a return channel via satellite (DVB-RCS) and satellite community efforts in term of interoperability over the last few years leads to quite a positive outcome: geostationary satellite networks are intended to provide broadband access to interactive multimedia services in low-infrastructure areas. However, in order to take in account real-time multimedia traffic, an efficient resource management scheme is still necessary to maximize the scarce uplink capacities usage. To address this capacity issue, this paper proposes a complete DVB-RCS QoS architecture that is implemented, thanks to an emulation platform, and evaluated with real multimedia applications. This paper first gives an overview of the QoS architecture usually used in DVB-S/RCS satellite system, especially in layers 2 and 3. It then introduces the satellite system emulation used in the experimentation and its calibration. The main contribution of this work focuses on the signaling principle designed to allow applications to take benefit from the QoS features of the satellite system even if they are non-QoS aware. It is then shown how signaling in such QoS architecture allows the user to change dynamically the QoS of his application using QoS agent and QoS server applications even if the application is not QoS-aware. It is also given quantitative results related to such a dynamic QoS change in the experiments done on the satellite emulation system.

Channel-Aware Scheduling for QoS and Fairness Provisioning in IEEE 802.16/WiMAX Broadband Wireless Access Systems

In the last few years, standardization activities within the IEEE 802.16 Working Group have resulted in the publication of specifications for an air interface of Fixed broadband wireless access systems. WiMAX is the commercial name of products compliant with the approved IEEE 802.16 standard. Although the standard suggests the main principles in designing a QoS architecture to support multimedia broadband services, implementation details are left to manufacturers. This article addresses a channel-aware scheduling algorithm conceived for a point-to-multipoint WiMAX architecture. It aims at enabling downlink traffic delivery with differentiated service treatment, even in nonideal channel conditions. A technique to compensate for channel errors is proposed to preserve QoS and fairness of a WF2Q+ based scheduling algorithm. The performance behavior of the proposed algorithm is confirmed by the outputs of a comprehensive simulation campaign.

A Performance Model and Measurement Framework for DiffServ Implementations

Providers of data network services are in search of new solutions for service offerings over integrated service packet networks which can accommodate voice and video traffic in addition to data traffic. The goal is to provide users with cutting-edge services such as IP telephony, video conferencing, video on demand, telemedicine, etc. As the traditional design of data networks has had little or no support in providing the required traffic characteristics to voice and video streams, architectures for quality of service (QoS) have been defined. Of these architectures, differentiated services (DiffServ) is seen as a significant contributor to the migration of current data networks to next-generation networks capable of providing a broader range of services. However, the way they have been defined, these architectures lack precise formal specifications, and therefore, their performance is strongly related to the quality of each implementation. This paper presents an abstract model for DiffServ with assured forwarding (AF) per-hop behavior (PHB). The model is meant for a better illustration of the dynamics of QoS parameters. After a thorough review of existing methodologies for performance measurements for DiffServ, this paper proposes a dynamic model for AF and a framework for its performance measurement, which is illustrated by a number of experiments run on a live network (NCIT*net 2). This paper is the starting point for the detailed specification of DiffServ PHBs. Experimental results illustrate, verify, and justify the model introduced.

Enhanced UPnP QoS Architecture for Network-adaptive Streaming Service in Home Networks

The existing versions of UPnP QoS architecture have several limitations associated with how they provide QoS-guaranteed streaming service over dynamically time-varying networks. In this paper, an enhanced UPnP QoS architecture is proposed to support network-adaptive media streaming in home networks. The proposed streaming scheme is verified by realizing a prototype implementation over an UPnP streaming testbed.

A quality-of-service signaling architecture for seamless handover support in next generation, IP-based mobile networks

The coupling of signaling protocols for mobility management and resource reservation plays an important role to achieve Quality-of-Service (QoS) in wireless environments. When performing a handover, request and allocation of resources have to be done in the shortest possible time to avoid disruptions for the user service. Therefore, it is preferable to ensure resource availability in advance, which we call anticipated handover. This approach for providing seamless handovers in turn poses challenges for the overall design of the QoS architecture and its associated QoS signaling protocol. This article describes the design, implementation, and evaluation of a comprehensive QoS architecture and a suitable QoS signaling protocol. It discusses intrinsic problems of reservations in IP based networks such as session ownership as well as a number of protocol design issues regarding the integration of QoS signaling with other protocols, such as Mobile IP. In particular, we define an end-to-end QoS architecture and a mobility-aware reservation signaling protocol Mobility Aware Reservation Signaling Protocol (MARSP) that supports anticipated handover, thus enabling seamless services over heterogeneous wireless access networks. The presented architecture and protocol were implemented and evaluated by measurements. They show that anticipated handovers not only outperform hard handovers regarding handover latency, but that they also provide functional and robustness advantages.

QoS policies and architecture for cache/memory in CMP platforms

As we enter the era of CMP platforms with multiple threads/cores on the die, the diversity of the simultaneous workloads running on them is expected to increase. The rapid deployment of virtualization as a means to consolidate workloads on to a single platform is a prime example of this trend. In such scenarios, the quality of service (QoS) that each individual workload gets from the platform can widely vary depending on the behavior of the simultaneously running workloads. While the number of cores assigned to each workload can be controlled, there is no hardware or software support in today's platforms to control allocation of platform resources such as cache space and memory bandwidth to individual workloads. In this paper, we propose a QoS-enabled memory architecture for CMP platforms that addresses this problem. The QoS-enabled memory architecture enables more cache resources (i.e. space) and memory resources (i.e. bandwidth) for high priority applications based on guidance from the operating environment. The architecture also allows dynamic resource reassignment during run-time to further optimize the performance of the high priority application with minimal degradation to low priority. To achieve these goals, we will describe the hardware/software support required in the platform as well as the operating environment (O/S and virtual machine monitor). Our evaluation framework consists of detailed platform simulation models and a QoS-enabled version of Linux. Based on evaluation experiments, we show the effectiveness of a QoS-enabled architecture and summarize key findings/trade-offs.

SPAD: A distributed middleware architecture for QoS enhanced alternate path discovery

In the next generation Internet, the network will evolve from a plain communication medium into one that provides endless services to the users. These services will be composed of multiple cooperative distributed application elements. We name these services overlay applications . The cooperative application elements within an overlay application will build a dynamic communication mesh, namely an overlay association . The Quality of Service (QoS) perceived by the users of an overlay application greatly depends on the QoS experienced on the communication paths of the corresponding overlay association . In this paper, we present super-peer alternate path discovery (SPAD), a distributed middleware architecture that aims at providing enhanced QoS between end-points within an overlay association . To achieve this goal, SPAD provides a complete scheme to discover and utilize composite alternate end-to-end paths with better QoS than the path given by the default IP routing mechanisms.

QoS 보장을 위한 UMTS와 WLAN의 인터워킹 구조

최근 Universal Mobile Telecommunication System (UMTS)와 Wireless Local Area Network (WLAN)의 장점을 효율적으로 사용하기 위한, 두 네트워크의 인터워킹 구조에 대한 연구가 활발히 진행되고 있다. 하지만 UMTS와 WLAN은 그 전송량의 차이가 커서, 전송 품질이 저하되기 쉽다. 그러므로 본 논문에서는 tight coupling을 기반으로 이동성 예측 기법을 이용한 동적인 서비스 품질 (QoS: Quality of Service)을 보장해주기 위한 두 네트워크 간 인터워킹 구조를 제안한다. 또한, 이렇게 제안한 인터워킹 구조를 ns-2로 시뮬레이션 하였으며, 그 결과 제안하는 인터워킹 구조가 기존의 인터워킹 구조에 비해 핸드오프 손실률을 줄이고, 핸드오프 순간 QoS를 제공해주지 않는 방법보다 훨씬 더 많은 양의 패킷을 전송한다는 것을 알 수 있다. Universal Mobile Telecommunications System (UMTS) and Wireless Local Area Network (WLAN) have been developed independently. Then, many researchers have studied UMTS-WLAN interworking architecture for the efficiency. However, the transmission capacity difference of two networks causes the transmission quality degradation. Therefore, this paper proposes a UMTS-WLAN interworking architecture for Quality of Service (QoS). The proposed architecture is based on tight coupling and dynamically guarantees QoS by the mobility prediction method. The proposed architecture is simulated by ns-2. Performance experimental results show that the proposed architecture reduces the handover dropping probability comparing with the existing method and enhances the amount of receiving packets comparing with the method without guaranteeing QoS.

DSL 광대역 접속망에서 DiffServ QoS 지원 방안

인터넷상에서 IP QoS를 제공하기 위한 IntServ와 DiffServ 구조 중 현재 DiffServ가 기술적, 경제적으로 현실적인 방안으로 받아들여지고 있다. 본 논문에서는 DSL 광대역 접속망에 적용될 수 있는 몇 가지 DiffServ QoS 지원 방안을 제시하고, 각 방안의 장단점 분석을 통해 기존 최선형 DSL망으로부터 DiffServ QoS지원 DSL망으로의 바람직한 이행 경로를 제시하고자 한다. DSL망은 전 세계적으로 최근에 매우 광범위하게 구축되어 있기 때문에 DiffServ QoS 지원 방안 설계 시에 다양한 QoS 서비스의 효율적인 제공뿐만 아니라, QoS 지원을 위한 신규 투자비용, 기존의 QoS 미지원 시스템과의 호환성, 기존 과금 체계와의 호환성 등이 중요하게 고려되어야 한다. 본 논문은 DSL망을 위한 DiffServ QoS 지원 방안들을 단기적으로 적용할 수 있는 정적 DiffServ 방안과 장기적으로 적용할 수 있는 동적 DiffServ 방안으로 구분하여 제시한다. 정적 DiffServ 지원 방안은 가입자 단위의 DiffServ QoS를 제공하는 평면적 DiffServ와 가입자 단위의 DiffServ QoS와 서비스 단위의 DiffServ QoS를 동시에 제공하는 구조적 DiffServ 방안을 포함하고, 동적 DiffServ 방안은 P2P(Peer to Peer) 멀티미디어 응용에 적용될 수 있는 직접 DiffServ와 ASP(Application Service Provider) 응용에 적용될 수 있는 간접 DiffServ를 포함한다. From both techlical and economic viewpoints, DiffServ IP QoS architecture is accepted as a more practical solution because of the complexity Problem of the other IntServ architecture. In this paper, we propose several models to support DiffServ QoS in DSL broadband access networks and discuss about migration path from current best-effort DSL networks to DiffServ-enabled ones. Since DSL networks are recently and widely deployed in the world amount ot new investment, compatibility with existing QoS-unaware DSL systems, and compatibility with existing charging systems as well as effective support of various QoS services must be carefully considered when we design DiffServ QoS support models in DSL networks. The DiffServ models proposed in this paper are divided into static DiffServ models and dynamic DiffServ models which are near-term solutions and long-term solutions repecitively. The static DiffServ models include Flat DiffServ which suworts per-subscriber DiffServ QoS and Structured DiffServ which supports per-subscriber and per-service DiffServ QoS. And the dynamic DiffServ models include Direct DiffServ for P2P(Peer to Peer) applications and Indirect DiffServ for ASP(Application Service Provider) applications.

Policy Based QoS Architecture for Media Streaming in UMTS

Policy Based QoS Architecture for Media Streaming in UMTS

An Efficient Routing Algorithm for Overlay Multicast in Diffserv Domains

We propose a novel approach to enable QoS-guaranteed overlay multicast among Diffserv domains. Our approach exploits the edge routers as the overlay nodes while complying with the core-stateless principle of the Diffserv architecture. The contribution of our work is two-fold. First, we devise a distributed insertion and relocation algorithm (DIRA) to organize the edge routers of the same domain into an efficient overlay multicast tree. The algorithm keeps a candidate parent for each node so that as the incremental tree building process is going on, the tree topology can be adjusted timely for a small cost according to its dynamic membership. Due to its distributed nature, the algorithm imposes no huge computation burden on any single node. Second, our approach combine the overlay multicast technique with the QoS architecture seamlessly, which provides a promising platform for various applications. Through a large amount of simulations, we prove that DIRA is more competitive than other IP multicast and overlay multicast schemes in terms of tree cost and other metrics.

New architecture of IP QoS management system

Based on the analysis of current Quality of Service (QoS) management on IP network, new generation of QoS architecture QoSAF is proposed. QoSAF is divided into three layers: resource control layer, network service layer and business layer. QoS management is accomplished by interactivity of layers. In this architecture, mechanism of feedback control enhances the functions of resource management and system monitoring. The principle of design and logical architecture of system is discussed in detail.

Joined MAC Scheduling and Transport Format Choice for UMTS Uplink Transmission

This paper deals with the description of the QoS architecture developed in the framework of the IST VIRTUOUS and SAILOR projects, especially targeting at the design of an UMTS MAC scheduling algorithm in charge of managing several uplink parallel active logical channels at User Equipment side. The joined approach to the packet scheduling and transport format choice proposed in this paper shows better performances respect to the 3GPP standard solution, mainly when the number of logical channels of different types --- i.e. logical channels with different needs in terms of maximum allowed delay --- handled by the same User Equipment increases. Furthermore, the proposed MAC design introduced in this paper allows a better exploitation of the available bandwidth in the uplink UMTS Radio Access Network, also increasing fairness between IP datagrams belonging to different sources.

Dynamic Application Profiles using Neural Networks for adaptive quality of service support in the Internet

The Internet continues to evolve into a network that supports a wide spectrum of applications with diverse requirements. The introduction of multimedia poses delay, throughput and packet loss requirements towards the network and makes the provision of QoS a very important issue. In this paper, we present the concept of Dynamic Application Profiles for the transparent support of QoS in the Internet. The paper builds on existing work on a distributed QoS architecture, and uses intelligent mechanisms, such as Neural Networks, in an effort to provide dynamic QoS to network applications in a fashion comprehensible to the average end user.

QoS Routing with Bandwidth and Hop-Count Consideration: A Performance Perspective

QoS Routing has been studied to provide evidence that it can increase network utilization compared to routing that is insensitive to QoS traffic requirements. However, because of its complexity, QoS routing is still the missing piece in a fully-fledged QoS architecture for the Internet. This paper exposes in detail the relationship between the routing algorithm and network condition (traffic load and the scale of the network topology) in different scenarios. We demonstrate that network size affects the performance, and give evaluation of different locations of source-destination pairs. We also point out the importance of using length of route as a metric to evaluate algorithms. This has seldom been used in previous simulation studies. This work confirms and extends earlier studies, and offers new insights for designing efficient QoS routing algorithms for future large- scale networks.

A new algorithm for traffic conditioners to improve proportional fairness in IP networks

The current trend in telecommunications networks addresses an All-IP vision, since most user applications are based on IP, and additionally, IP networks operation is simpler than other more complex ones. These new trends in multimedia communications are giving rise to an increasing need of quality of service (QoS). The Differentiated Services (DiffServ) QoS architecture will provide the means to help underlying technologies, like MPLS, to guarantee the QoS required to support data and real-time services. In DiffServ, QoS is mainly provided with traffic control at edge nodes, and this task is carried out by traffic conditioners. In this paper, we introduce a new policy function for traffic conditioning. Its ability to react to new network conditions makes end-users to get excess bandwidth in proportion to their contracted target rates. We call this method Proportional Excess Traffic conditionER (PETER). Through extensive simulations, we confirm the effectiveness of our approach in providing both a proportional excess bandwidth distribution and assured contracted target rates.

A survey of envelope processes and their applications in quality of service provisioning

Provisioning of quality of service (QoS) guarantees has become an increasingly important and challenging topic in the design of the current and the next-generation Internet. The class of envelope processes (EPs) is one of the key elements for many QoS provisioning mechanisms. An arrival EP A(τ) (or a service curve) bounds the cumulative traffic of a flow (or the cumulative service a flow receives) over any interval of length τ. Such bounds can be deterministic or probabilistic, and can be used for provisioning of deterministic or statistical service guarantees. In this article we provide a survey on arrival EPs and service curves. We provide an overview of various EPs proposed in the literature during the last 15 years and discuss their applications and performance in QoS provisioning. We aim to provide a big picture of the existing work. There is considerable research effort addressing QoS issues in resource-constrained access networks (such as wireless networks) and in the new multiprotocol label switching (MPLS) and peer-to-peer (P2P) networking paradigms. We aim to provide a comprehensive survey of existing work, which can yield useful insights, and help the development of new QoS metrics, mechanisms, and architectures for emerging network environments.

Integrated Services on High Altitude Platform: Receiver Driven Smart Selection of HAP-Geo Satellite Wireless Access Segment and Performance Evaluation

A renewed interest in the development of high-altitude platforms (HAPs), which are stratospheric aircraft or airship carrying payloads tailored for a wide range of applications in telecommunications and remote sensing, is becoming progressively widespread. HAPs offer a reduced propagation delay and they are especially suitable for interactive multimedia services. In this paper, the inter-working between HAP and satellite segments in an integrated QoS architecture has been addressed. A new way to manage integrated services over a new hybrid wireless platform has been proposed. A smart terminal device has been considered in order to perform an intelligent switching on the wireless access segment. The switching criteria applied in the HAP/satellite architecture is based on the available bandwidth and on the admissible data packet end-to-end delay. Performance evaluations of the integrated HAP–satellite platform have been evaluated in terms of bandwidth utilization and number of admitted calls. The simulations show an improvement of admitted calls, reduced data packet end-to-end delay and increased bandwidth utilization.

Utility-based resource allocation and scheduling in OFDM-based wireless broadband networks

This article discusses downlink resource allocation and scheduling for OFDM-based broadband wireless networks. We present a cross-layer resource management framework leveraged by utility optimization. It includes utility-based resource management and QoS architecture, resource allocation algorithms, rate-based and delay-based multichannel scheduling that exploits wireless channel and queue information, and theoretical exploration of the fundamental mechanisms in wireless resource management, such as capacity, fairness, and stability. We also provide a solution that can efficiently allocate resources for heterogeneous traffic with diverse QoS requirements.

The use of service level agreements in tactical military coalition force networks

Tactical military coalition force IP networks will have to offer quality of service. Service level agreements and service level specifications are important elements of the QoS architecture in civilian networks. However, SLAs/SLSs in military coalition networks should not be applied in the same fashion as in a commercial network. Our contribution is to identify the useful role SLAs/SLSs can play in network engineering and QoS management of tactical coalition force networks. The SLS definition needs to be more detailed than for a commercial SLS, and its monitoring must be performed on a finer timescale than in comparable commercial networks. The security architecture of military coalition networks may also restrict the monitoring and SLA management. Finally, we sketch a measurement-based approach showing how SLSs can be used in tactical military coalition force networks to support both call admission control and network engineering. Parts of this analysis include a discussion of SLSs and the proposed NATO standards for tactical communications network.