A comprehensive platform to manage peer churn and bandwidth fluctuations in real-time multimedia P2P networks

In the last few years, new service providers are growing in the Internet scenario to create new multimedia services. The most common approach to this end is based on peer-to-peer (P2P) networks. The new service providers are manifesting great interest not only for classical multimedia applications, like video streaming and video on demand, but also for multi-party games, private video-chat rooms, videoconference and real-time video teaching, usually containing a small number of high-interactive group members. The target of this paper is to define a multipoint multimedia communication platform for such kind of applications, accounting both peer set variation (peer arrivals and departures) and peer bandwidth modifications. In addition, a revenue model for providers of this kind of services is proposed to allow them to design their networks in order to maximize their revenue while satisfying user requirements in terms of both admission rejection probability and perceived quality on the received video stream.     

QoE assessment model for multimedia streaming services using QoS parameters

This paper proposes a video QoE (Quality of Experience) assessment model which can assess video quality of experience with only QoS (Quality of Service) parameters and their relative importance at network layer. Since network or service providers can forecast whether to provide multimedia services above a certain level of service quality using the proposed model, they can offer and maintain optimum network environment for multimedia service such as IPTV. Through an experiment of video quality comparison we show that our QoS/QoE correlation model is closely related with video quality degradation patterns to network environmental change.     

Distributed computing architecture for effective management of multimedia streams on DPE

We study a networking architecture model that is built on a distributed processing environment (DPE) for multimedia services suitable for high speed transport networks such as ATM networks. In this architecture, the applications are deployed as units of software building blocks. Each building block provides a layered view for the effective management and control of the multimedia network resources and services according to the concept of telecommunications management network (TMN) and telecommunications information networking architecture (TINA). For the purpose of flexible service provision to users and effective service introduction by service providers, this architecture proposes the adoption of ad hoc service building blocks such as a video on demand building block and a CSCW building block that have interactions with a general purpose building block. This paper also proposes a naming structure for the management of user profiles and session profiles using a directory service system, and an effective control model for multimedia logical device objects using a stream process approach. The proposed model is implemented on a DPE platform that provides various transparencies, ANSAware.     

Algorithms for Web service selection with static and dynamic requirements

A main feature of Service Oriented Architectures is the capability to support the development of new applications through the composition of existing Web services that are offered by different service providers. The runtime selection of which providers may better satisfy the end-user requirements in terms of quality of service remains an open issue in the context of Web services. The selection of the service providers has to satisfy requirements of different nature: requirements may refer to static qualities of the service providers, which do not change over time or change slowly compared to the service invocation time (for example related to provider reputation), and to dynamic qualities, which may change on a per-invocation basis (typically related to performance, such as the response time). The main contribution of this paper is to propose a family of novel runtime algorithms that select service providers on the basis of requirements involving both static and dynamic qualities, as in a typical Web scenario. We implement the proposed algorithms in a prototype and compare them with the solutions commonly used in service selection, which consider all the service provider qualities as static for the scope of the selection process. Our experiments show that a static management of quality requirements is viable only in the unrealistic case where workload remains stable over time, but it leads to very poor performance in variable environments. On the other hand, the combined management of static and dynamic quality requirements allows us to achieve better user-perceived performance over a wide range of scenarios, with the response time of the proposed algorithms that is reduced up to a 50 % with respect to that of static algorithms.     

Self-adaptable media service architecture for guaranteeing reliable multimedia services

The main objective of this paper is to design and develop a Self-Adaptable Media Service Architecture (SAMSA) for providing reliable dynamic composite multimedia service through policy-based actions. The multimedia services such as media retrieval, transcoding, scaling and display services are combined based on the preferences of the user to create a dynamic composite multimedia service called as Video-on-Demand service. Such distributed multimedia services deployed using Service Oriented Architecture (SOA) can be accessed in heterogeneous environments that are prone to changes during run-time. To provide reliable and adaptive multimedia services, a powerful self-adaptable architecture with dynamic compositions of multimedia services is necessary to adapt during run-time and react to the environment. The adaptability in this proposed architecture is achieved by enabling the service providers to Monitor, Analyze and Act on the defined policies that support customization of compositions of multimedia services and guarantee the Quality of Service (QoS) provisioning. The Media Service Monitor (MSM) observes the business and quality metrics associated with the multimedia services during run-time. The monitored results are analyzed by Monitored Results Analyzer (MRA) which identifies the type and location of the fault. The Adaptive Media Service Manager (AMSM) takes corrective actions based on the monitored results, through the policies defined as an extension of WS-Policy (Web Service—Policy framework). The effectiveness of the proposed Self-Adaptable Media Service Architecture (SAMSA) has been evaluated on Dynamic Composite Real-time Video-on-Demand Web Service (DCRVoDWS) for a maximum of 200 simultaneous client’s requests. The analysis of results shows that the proposed architecture provides better improvement on reliability, response time and user satisfaction.     

Quality management in service ecosystems

Service-oriented architectures and Web services mature and have become more widely accepted and used by industry. This growing adoption increased the demands for new ways of using Web service technology. Users start re-combining and mediating other providers’ services in ways that have not been anticipated by their original provider. Within organisations and cross-organisational communities, discoverable services are organised in repositories providing convenient access to adaptable end-to-end business processes. This idea is captured in the term Service Ecosystem. This paper addresses the question of how quality management can be performed in such service ecosystems. Service quality management is a key challenge when services are composed of a dynamic set of heterogeneous sub-services from different service providers. This paper contributes to this important area by developing a reference model of quality management in service ecosystems. We illustrate the application of the reference model in an exploratory case study. With this case study, we show how the reference model helps to derive requirements for the implementation and support of quality management in an exemplary service ecosystem in public administration.     

Extending TINA with Secure On-Line Accounting Services

Concepts and principles of TINA (Telecommunications Information Networking Architecture) are introduced with the objective of correcting problems of the current centralized service control and service data model in an IN (Intelligent Network). It is becoming increasingly clear that the future sophisticated telecommunication services, e.g., multimedia, and multi-party conferencing, breaking away from the traditional telephony call model will need the solutions for rapid and efficient introduction, deployment, operations, and management.In this paper, we discuss accounting features and requirements, as well as security services in the TINA management context. We will introduce and present an implementation of a model for a security management, based on secure objects, cryptography and certificate distribution. In order to provide secure services, secure objects that have security functionality, such as authentication and access control, have been defined. Secure objects in our model are CORBA objects. The security domain is also called SBS (Security Base Server), provides security services and has an SMIB (Security Management Information Base) that contains security policies, cryptographic algorithms, and other relevant information. A prototype has been implemented and some experimental results are presented.     

A framework for identity privacy in SIP

Secure multimedia delivery in modern and future networks is one of the most challenging problems towards the system integration of fourth generation (4G) networks. This integration means that different service and network providers will have to interoperate in order to offer their services to end users. This multidomain environment poses serious threats to the end user who has contract with, and trusts only a limited number of operators and service providers. One such threat is end users’ privacy on which we will focus in this paper. Probably the most promising protocol for multimedia session management is the Session Initiation Protocol (SIP), which is an application layer protocol and thus can operate on top of different lower layer technologies. SIP is quite popular and a lot of research has been conducted; however, it still has some security issues, one of which is related to privacy and more particularly the protection of user identities (IDs). In this paper we comment on the ID privacy issue of SIP and propose a framework called PrivaSIP that can protect either the caller's ID or both the caller's and the callee's IDs in multidomain environments. We present different implementations of our framework based on asymmetric and symmetric cryptography analyzing the pros and cons of each one of them. Furthermore, we provide performance measurements in order to estimate the performance penalty of our framework over standard SIP. The most significant advantage of our method is that it can assure user ID protection even when SIP messages are transmitted through untrusted SIP domains, while our results show that this can be achieved with no perceived delay by the end user.     

Data mining based multi-level aggregate service planning for cloud manufacturing

Cloud manufacturing (CMfg) promotes a dynamic distributed manufacturing environment by connecting the service providers and manages them in a centralized way. Due to the distinct production capabilities, the service providers tend to be delegated services of different granularities. Meanwhile, users of different types may be after services of different granularities. A traditional aggregate production planning method is often incapable of dealing with type of problems. For this reason, a multi-level aggregate service planning (MASP) methodology is proposed. The MASP service hierarchy is presented, which integrates the services of different granularities into a layered structure. Based on this structure, one of data mining technologies named time series is introduced to provide dynamic forecast for each layer. In this way, MASP can not only deal with the services of multi-granularity, but also meet the requirements of all related service providers irrespective of their manufacturing capabilities. A case study has been carried out, showing how MASP can be applied in a CMfg environment. The results of the prediction are considered reliable as the order of magnitude of the production for each service layer is much greater than that of the corresponding mean forecast error.     

An open framework supporting multimedia web services

With the rapid emergence of Web services, more and more Web services are published on the Internet as resources for Web application development. There may exist some relationships among different Web services, such as exact match, plug-in match, and irrelevant. In this paper, we discuss a set of requirements related to multimedia Web services, and propose a three-tier framework to establish an open environment supporting multimedia Web services, while partially implementing the requirements. This paper focuses on the design of the service broker tier that is essential for future Web services-oriented system design and integration and enabling Web services more transparent, interoperable, and fault-tolerate.     

Composing Web Services: A QoS View

An Internet application can invoke several services--a stock-trading Web service, for example, could invoke a payment service, which could then invoke an authentication service. Such a scenario is called a composite Web service, and it can be specified statically or established dynamically. Dynamic composition of Web services requires service consumers to discover service providers that satisfy given functional and nonfunctional requirements including cost and QoS requirements such as performance and availability. In previous columns, I've examined how quality of service (QoS) comes into play for service providers, consumers, and parallel transactions. Here, I'll show how it fits into composite Web services.     

FCM-based customer expectation-driven service dispatch system

Maintaining long-term customer loyalty has been an important issue in the service industry. Although customer satisfaction can be enhanced with better service quality, delivering appropriate services to customers poses challenges to service providers, particularly in real-time and resource-limited dynamic service contexts. However, customer expectation management has been regarded as an effective way for helping service providers achieve high customer satisfaction in the real world that is nevertheless less real-time and dynamic. This study designs a FCM-based customer expectation-driven service dispatch system to empower providers with the capability to deal effectively with the problem of delivering right services to right customers in right contexts. Our evaluation results show that service providers can make appropriate decisions on service dispatch for customers by effectively managing customer expectations and arranging their contextual limited resources and time via the proposed service dispatch system. Meanwhile, customers can receive suitable service and obtain high satisfaction when appropriate services are provided. Accordingly, a high-performance ecosystem can be established by both service providers and customers who co-create value in the dynamic service contexts.     

SDN云网平台的服务质量模型研究

基于SDN的云网平台逐渐得到广泛应用,云网平台所提供服务的质量评价也越来越受到关注。考虑了云网平台服务所具有的通用云服务和软件化的特点,从服务提供者和用户两个视角出发,对服务质量模型的设计进行了需求分析,并获得服务质量模型的分类维度;参考SQuaRE等国际标准,提出了云网平台服务质量模型QM-SDNCCP,并给出了度量元的计算方法,以达到描述并量化评价云网平台服务质量的目的;对QM-SDNCCP进行了信度分析,表明QM-SDNCCP模型的特性和子特性的设计具有可靠性和一致性。QM-SDNCCP可以应用在技术选型、验收、运维和服务使用阶段,为服务提供者和用户提供云网平台服务选择和质量改进的参考。     

Quality of Service Negotiation for Commercial Medical Grid Services

The GEMSS project has developed a service-oriented Grid that supports the provision of medical simulation services by service providers to clients such as hospitals. We outline the GEMSS architecture, legal framework and the security features that characterise the GEMSS infrastructure. High levels of quality of service are required and we describe a reservation-based approach to quality of service, employing a quality of service management system that iteratively finds suitable reservations and uses application specific performance models. The GEMSS Grid is a commercial environment so we support flexible pricing models and a FIPA reverse English auction protocol. Signed Web Service Level Agreement contracts are exchanged to commit parties to a quality of service agreement before job execution occurs. We run four experiments across European countries using high performance computing resources running advanced resource reservation schedulers. These experiments provide evidence for our Grid’s rational behaviour, both at the level of service provider quality of service management and at the higher level of the client choosing between competing service providers. The results lend support to our economic model and the technology we use for our medical application domain.     

Formulating and managing viable SLAs in cloud computing from a small to medium service provider's viewpoint: A state-of-the-art review

In today's competitive world, service providers need to be customer-focused and proactive in their marketing strategies to create consumer awareness of their services. Cloud computing provides an open and ubiquitous computing feature in which a large random number of consumers can interact with providers and request services. In such an environment, there is a need for intelligent and efficient methods that increase confidence in the successful achievement of business requirements. One such method is the Service Level Agreement (SLA), which is comprised of service objectives, business terms, service relations, obligations and the possible action to be taken in the case of SLA violation. Most of the emphasis in the literature has, until now, been on the formation of meaningful SLAs by service consumers, through which their requirements will be met. However, in an increasingly competitive market based on the cloud environment, service providers too need a framework that will form a viable SLA, predict possible SLA violations before they occur, and generate early warning alarms that flag a potential lack of resources. This is because when a provider and a consumer commit to an SLA, the service provider is bound to reserve the agreed amount of resources for the entire period of that agreement – whether the consumer uses them or not. It is therefore very important for cloud providers to accurately predict the likely resource usage for a particular consumer and to formulate an appropriate SLA before finalizing an agreement. This problem is more important for a small to medium cloud service provider which has limited resources that must be utilized in the best possible way to generate maximum revenue. A viable SLA in cloud computing is one that intelligently helps the service provider to determine the amount of resources to offer to a requesting consumer, and there are number of studies on SLA management in the literature. The aim of this paper is two-fold. First, it presents a comprehensive overview of existing state-of-the-art SLA management approaches in cloud computing, and their features and shortcomings in creating viable SLAs from the service provider's viewpoint. From a thorough analysis, we observe that the lack of a viable SLA management framework renders a service provider unable to make wise decisions in forming an SLA, which could lead to service violations and violation penalties. To fill this gap, our second contribution is the proposal of the Optimized Personalized Viable SLA (OPV-SLA) framework which assists a service provider to form a viable SLA and start managing SLA violation before an SLA is formed and executed. The framework also assists a service provider to make an optimal decision in service formation and allocate the appropriate amount of marginal resources. We demonstrate the applicability of our framework in forming viable SLAs through experiments. From the evaluative results, we observe that our framework helps a service provider to form viable SLAs and later to manage them to effectively minimize possible service violation and penalties.     

Managing QoS for Multimedia Applications in the Differentiated Services Environment

The overall quality of network connections has a significant impact on the performance of networked applications. As a result, Quality-of-Service (QoS) management for networked multimedia applications over IP is a significant and immediate challenge. While differentiated services (DiffServ) provide a sense of resource allocation and QoS, they do not guarantee QoS. This paper presents the design, implementation and evaluation of a content-aware bandwidth broker (CABB) that manages QoS for multimedia applications in a DiffServ environment. CABB allocates network resources to multimedia flows based on client requirements, the adaptability of the application, and its tolerance to network level parameters such as bandwidth, delay, and latency. It has been implemented and evaluated using the NS-2 simulator toolkit. Evaluations show that CABB improves network resource allocations and increases overall throughput. Furthermore multimedia application flows are better managed and controlled, improving perceived QoS and avoiding possible congestion at core routers.     

Scalable multimedia delivery with QoS management in pervasive computing environment

People are increasingly demanding rich-media and bundled services. However, the diverse terminals, heterogeneous networks as well as various user requirements constrain the multimedia access to low quality in the pervasive computing environment. In order to enable rich-media delivery across a wide range of devices and networks, multimedia adaptation with scalable QoS management is an important issue. Our research introduces a Scalable Multimedia Delivery (SMD) framework with QoS management. This framework utilizes the CAM4Home metadata model to aggregate multimodal rich media services into a bundle. MPEG-21 metadata is integrated into the CAM4Home model to enforce interoperable QoS management. The issues in supporting QoS are addressed on both fidelity and modality. We further develop the SMD system in IP Multimedia Subsystem (IMS) architecture, where multimedia adaptation is implemented through application-level QoS negotiation.     

U-HMS: hybrid system for secure intelligent multimedia data services in Ubi-Home

Requirements for are rapidly increasing, such as multimedia services, automatic execution of intelligent services without manual commands from user, user-friendliness, transparency of use, and interoperability of multimedia data among incompatible devices. In addition, in order to provide secure multimedia data services, multimedia data protection and management, authentication, and authorization management methods that fit the purpose of the above demands are expected to be required. In this paper, ubiquitous-hybrid multimedia system for secure and intelligent multimedia data services in Ubi-Home is proposed. In addition, an authentication method suitable for the Ubi-Home is suggested. The proposed system provides intelligent services by reflecting context information (user preference, user location, device status information) through sensor network modules, providing transparent and secure multimedia service.     

Quality of Experience in Cloud services: Survey and measurements

Cloud-based systems are gaining enormous popularity due to a number of promised benefits, including ease of use in terms of deployment, administration and maintenance, high scalability as well as flexibility to create new services. However, as more personal and business applications migrate to the Cloud, the service quality becomes an important differentiator between providers, specially in the case of mobile operators. Quality of Experience (QoE) as perceived by the end-user has therefore the potential to become the guiding paradigm for managing quality provisioning and applications’ design in the Cloud. This paper presents the results of several Cloud QoE studies performed for different Cloud-based services, ranging from services with low requirements in terms of latency and interactivity (e.g., Cloud storage systems), multimedia On-Demand services (e.g., YouTube video streaming), communication and telepresence (e.g., Lync Online videoconferencing) to highly interactive services (e.g., Virtual Cloud Desktop). The results of these studies provide a ground truth basis for developing future Cloud services with QoE requirements, as well as for dimensioning the underlying network provisioning infrastructures, particularly with regard to mobile access technologies.