The EMA system: a CTI based e-mail alerting service

The integration of Internet services and telephony services is a new area for the development of telecommunications services. One example is an e-mail alerting service that uses the telephony network for e-mail notification. The EMA system is a computer telephony integration (CTI) application that checks a user's mailbox on the mail server and informs him/her over the phone when new e-mail arrives, eliminating the need for permanent Internet connection. The EMA system has a Web-based interface, enabling the user to configure service parameters. The EMA system is developed as a distributed and concurrent application. It consists of seven modules: the console, Web interface, Web handler, controller, voice machine, database, and mail checker, using communication solutions based on component object model (COM) technology. This article describes the structure of the EMA system, its implementation, and advantages for users     

Web service discovery utilizing logical reasoning and semantic similarity

Web service discovery facilitates the implementation of complex and reconfigurable applications in service‐oriented architecture, such as service selection, composition, and provision. This paper presents an approach for semantic and automated Web service discovery. Our approach to semantic Web service discovery consists of ontology‐based service preprocessor, reasoning‐based service filter, and parameter‐based service matcher. An important feature of this approach is that the relationship among concepts in ontology is quantified and considered as an important factor in the matching process, which results in high precision and recall. Additionally, we propose a filtering method based on logical reasoning to preprocess the large amount of Web services. Through the filtering method, Web services which are feasible in logic are selected to be matched with user requests. So there is a great improvement in the run‐time performance of service discovery approach. Experiments show that our approach is feasible and effective to discover the required Web services.     

The Representation and Computation of QoS Preference with Its Applications in Grid Computing Environments

In Grid computing environment, quality of service (QoS) provisioning must be provided to the end users on the basis of their specific requirements. This paper proposes in a first step QoS attributes for Grid applications. In this matter, a mix of quantitative and qualitative parameters have to be considered. In the context, the analytical hierarchy process (AHP) technique [1] is a possible approach to formulate the QoS requirements of the users for Grid services. In order to apply QoS preference to actual application, we introduce a QoS function and a metric for user's satisfaction degrees. These both tools can be used as an evaluation criterion by the user. Subsequently, an algorithm of service selection considering the user's QoS preference is presented. Our empirical studies indicate that the application can reliably select the optimal service for users.     

The Grid Application Toolkit: Toward Generic and Easy Application Programming Interfaces for the Grid

Core Grid technologies are rapidly maturing, but there remains a shortage of real Grid applications. One important reason is the lack of a simple and high-level application programming toolkit, bridging the gap between existing Grid middleware and application-level needs. The Grid Application Toolkit (GAT), as currently developed by the EC-funded project GridLab, provides this missing functionality. As seen from the application, the GAT provides a unified simple programming interface to the Grid infrastructure, tailored to the needs of Grid application programmers and users. A uniform programming interface will be needed for application developers to create a new generation of "Grid-aware" applications. The GAT implementation handles both the complexity and the variety of existing Grid middleware services via so-called adaptors. Complementing existing Grid middleware, GridLab also provides high-level services to implement the GAT functionality. We present the GridLab software architecture, consisting of the GAT, environment-specific adaptors, and GridLab services. We elaborate the concepts underlying the GAT and outline the corresponding application programming interface. We present the functionality of GridLab's high-level services and demonstrate how a dynamic Grid application can easily benefit from the GAT. All GridLab software is open source and can be downloaded from the project Web site.     

An Approach to Integrating SIP in Converged Multimodal/Multimedia Communication Services

In this paper, we present an approach of integrating SIP (Session Initiation Protocol) in converged multimodal/multimedia communication services. An extensible VoIPTeleserver for VoIP in SIP environment is described. It is based on the concept of dialogue system and Web convergence that separates the channel dependent media resources from the application dependent service creation and hosting environment. It supports XML based service applications for multiple channels including voice, DTMF, IM and chat over IP. The loosely coupled open architecture in our approach is highly extensible. We describe the concept and structure of VoIPTeleServer used in our approach in detail, which interfaces to the VoIP world through SIP signaling and works as a broker between the VoIP SIP environment and MTIP to deliver converged communication services. A prototype of VoIPTeleServer was implemented, and services and applications based on SIP and MTIP convergence are constructed. Special attention is given to the adverse effect of delay, jitter and packet loss for voice portal services over IP. In particular, case studies of DTMF service in voice portal under adverse channel conditions are performed. The compounding effects of multiple channel impairments to DTMF in voice portal services over IP are characterized. The potential high error rate of the DTMF service indicates that the data redundancy method as proposed in RFC 2198 is needed for DTMF in order to achieve reliable voice portal services over IP.     

Web service selection algorithm based on principal component analysis

Existing Web service selection approaches usually assume that preferences of users have been provided in a quantitative form by users. However, due to the subjectivity and vagueness of preferences, it may be impractical for users to specify quantitative and exact preferences. Moreover, due to that Quality of Service (QoS) attributes are often interrelated, existing Web service selection approaches which employ weighted summation of QoS attribute values to compute the overall QoS of Web services may produce inaccurate results, since they do not take correlations among QoS attributes into account. To resolve these problems, a Web service selection framework considering user’s preference priority is proposed, which incorporates a searching mechanism with QoS range setting to identify services satisfying the user’s QoS constraints. With the identified service candidates, based on the idea of Principal Component Analysis (PCA), an algorithm of Web service selection named PCA-WSS (Web Service Selection based on PCA) is proposed, which can eliminate the correlations among QoS attributes and compute the overall QoS of Web services accurately. After computing the overall QoS for each service, the algorithm ranks the Web service candidates based on their overall QoS and recommends services with top QoS values to users. Finally, the effectiveness and feasibility of our approach are validated by experiments, i.e. the selected Web service by our approach is given high average evaluation than other ones by users and the time cost of PCA-WSS algorithm is not affected acutely by the number of service candidates.     

基于定性多用户偏好的Web服务选择

随着Web服务数量逐渐增多,出现了许多服务提供者提供功能相同或相似服务的情况.如何在一些功能相似或相同的服务集合中,根据用户对服务质量的需求选出更符合用户要求的服务,是当前研究人员普遍关心的课题.本文提出一种定性的服务选择方法,用来解决涉及多个用户的Web服务选择问题.各用户对服务质量的需求被表示为偏好.提出的算法将能够综合考虑各个用户的偏好,使选出的服务尽可能满足大部分用户的偏好要求,并给出了一个实例说明该算法的应用.实验结果表明了算法的有效性.     

网格应用模型及方法研究

针对实现资源共享和协同工作的网格技术应用研究与发展现状，文章给出网格应用总体结构；根据Petri网系统特点，提出基于Petri网的服务流网SF—net模型，设计了基于UML的网格工作流程序的一般性开发方法。并在此基础上定义了基于Petri网的网格作业描述语言；讨论了当前工业界Web服务业务过程执行语言BPEL4WS及进程代数CSP与文中所提服务流网的结合，引入服务代数概念，表明了服务流网SF-net的灵活性。     

Semantics-based dynamic service composition

Complex services may be dynamically composed through combining distributed components on demand (i.e., when requested by a user) in order to provide new services without preinstallation. Several systems have been proposed to dynamically compose services. However, they require users to request services in a manner that is not intuitive to the users. In order to allow a user to request a service in an intuitive form (e.g., using a natural language), this paper proposes a semantics-based service composition architecture. The proposed architecture obtains the semantics of the service requested in an intuitive form, and dynamically composes the requested service based on the semantics of the service. To compose a service based on its semantics, the proposed architecture supports semantic representation of components [through a component model named Component Service Model with Semantics (CoSMoS)], discovers components required to compose a service [through a middleware named Component Runtime Environment (CoRE)], and composes the requested service based on its semantics and the semantics of the discovered components [through a service composition mechanism named Semantic Graph-Based Service Composition (SeGSeC)]. This paper presents the design, implementation and empirical evaluation of the proposed architecture.     

基于语义Web服务的智能电信业务模型

该文针对电信业务领域用户需求多样化的实际情况,将互联网领域语义Web服务模型进行完善,提出了基于语义Web服务的智能电信业务模型。在模型中,设计了电信业务领域本体库,实现了电信业务领域知识的共享;提出了基于本体的用户个性数据库,利用本体的天然推理特性加强对用户个性的挖掘;引入了智能代理,将用户从浩淼的服务选择中解放出来。设计了语义转换XSLT代码生成模块提高了语义Web服务描述效率。该模型已经在实际的测试环境中得到验证,最后以流媒体业务为例,说明了该模型的工作原理。     

TOPS: an architecture for telephony over packet networks

Packet telephony is of increasing interest in both the telecommunications and Internet communities. The emergence of packet telephony will create new services, and presents an opportunity to rethink how conventional telephony services are implemented. In this paper, we present an architecture for telephony over packet networks (TOPS). TOPS allows users to move between terminals or to use mobile terminals while being reachable by the same name. TOPS users can have multiple terminals and control how calls are routed to them. TOPS allows for terminals with a range of capabilities such as support for video, whiteboard, and other media with a variety of coding formats. TOPS retains the necessary information on terminal capabilities to determine the appropriate type of communication to be established with the remote terminal. The architecture assumes that the underlying network supports the establishment of end-to-end connectivity between terminals, with an appropriate quality of service. The components of TOPS are a directory service, an application layer signaling protocol, and a logical channel abstraction for communication between end-systems. The directory service maps a user's name to a set of terminals where the user may be reached. A user can control the translation operation by specifying profiles that customize how his name is mapped to a set of terminals where he can be reached. Terminal capabilities are also stored in the directory service. The application layer signaling protocol establishes and maintains call state between communicating terminals. The logical channel abstraction provides a shared end-to-end context for a call's constituent media and control streams, while isolating the applications from the details of the network transport mechanisms. In addition to supporting simple point-to-point calls, the architecture supports both centralized and decentralized conferencing. We also introduce a simple encapsulation format for voice     

一种基于NGOD架构的云应用服务管理方案

介绍了一种基于NGOD架构的云应用服务管理方案。通过对NGOD架构进行扩展,增加了应用服务器和应用服务器管理器两个模块,将个人计算机和手机、平板计算机等智能终端上的软件应用部署到广电网上,为用户提供更多更好的服务。     

NGN的演进和Web Service技术

开放和融合是网络发展的趋势。ITU提出了GII(Global Information Infrastructure)的概念模型,从企业和用户的视点描述了电信网络演进的方向,并提出了ICA(Information Communication Architecture),详细描述了GII概念模型中的中间件功能。同时,在计算机界,网格技术和Web Service技术结合,形成了OGSA(Open Grid Service Architecture)的架构。结合Web Service技术,GII、ICA的功能可以表示为Web Service的集合,网络提供给用户的服务可以是Web Service服务,或者是Web Service组合后形成的更高粒度的服务。Web Service技术和NGN结合有利于网络的融合和开放,能够在传输网络之上形成一个业务网,必将促进NGN的发展。     

Location discovery in enterprise-based wireless networks: Case studies and applications

We have designed and implemented a Web service for location discovery (LODS) and a location-based printing service that usesLODS on a network with wirelessLAN connectivity based onIEEE 802.11 that is typical to campuses and enterprises. The need for location management and location-based services is linked to the mobility of the users. While location discovery is already implemented in cellular telecommunication networks since the system needs to know where are the users to connect them to incoming calls, the need for such a service was not so crucial in data network where in general the mobile user is the client and initiates the connections. We propose several solutions to implement our location discovery service depending on the underlying networking architecture and compare these solutions in terms of several criteria.LODS allows mobile users to find their approximate location within the campus or the enterprise and allows location-based applications to find out the location of a user to suggest the nearest points of interest, e.g., printers, elevators, and vending machines. We also present the case of our location-based remote printing service that was deployed in Purdue wireless network.     

Authentication with P2P Agents

The problem of network security is now heavily focused on user and agent authentication. In particular, higher levels of automated management and autonomous behaviour are economically necessary within security services. This work focuses on a peer-to-peer (P2P) network architecture in support of an authentication service application. The paper considers whether the key properties of P2P systems, such as scalability, robustness and resilience, may be of significant value in the context of designing a secure agent-based user authentication service. The task of authenticating legitimate network users across distributed systems and services remains a challenging process. The proposed solution is to use a distributed agent-based application to address the process of client authentication and the maintenance of user credentials. Using an agent-to-agent platform, an autonomous and scalable defence mechanism has been constructed. The agent architecture provides a number of security services with the goal of automating the process of user authentication and trust management. In particular, the agents handle all password, encryption keys and certificate management. This revised version was published online in July 2006 with corrections to the Cover Date.     

基于社会网络的语义Web服务发现模型

web服务发现模型是为了满足用户各种用途的web服务方式,以代码重入和松散耦合的方式以最优的组合实现可以提供用户需要的web服务模型。web服务发现模型是一种面向服务系统架构的一类基础性问题,但是又是解决用户不同需求十分有效的模型。通过对本体特性和发现模型的结构特点的研究,在本文中引入了本体解析的web服务标注算法和环境语义web发现模型。从而更好地实现web服务发现模型的选择用户所要求的服务的准确性,也为web服务的智能匹配做出了探索。     

Computational network federations: a middleware architecture for network-based computing

Computational Network Federations (CNFs) enable an arbitrary set of heterogeneous hosts which are connected via any type of network to form dynamic virtual distributed systems that cooperate to execute an application, or serve as generalized application service platforms to end users. CNFs motivate a view of the Internet as a vast unified host: a repository of information, application services, and an omnipresent supercomputing resource regardless of the type of access device or access methodology. CNFs provide a powerful way of virtualizing generalized enterprise networks (or even the Internet), and an economic and resilient model for deploying enterprise applications, (such as CRM) and peer-2-peer services (e.g., chatrooms). This paper describes a middleware architecture that enables network-based computing, communications, and services through a unified, access, and platform-independent approach. CNFs borrow from the capabilities of grid computing and aim toward intelligent computational service networks that are ubiquitous, secure, and adaptive to user and access-method idiosyncrasies. CNFs encompass a set of abstractions and interfaces that provide: 1) a unified service-oriented view of the network to the user; 2) a homogeneous host abstraction to applications; and 3) a shared-memory abstraction to software developers. This paper outlines the architecture of CNFs and describes in more detail i-DVM, a distributed multithreaded meta-OS that forms the core of a CNF and implements the virtual machine abstraction and location transparency.     

Hybrid model for dynamic evaluation of trust in cloud services

Cloud computing, a new paradigm in distributed computing, has gained wide popularity in a relatively short span of time. With the increase in the number, functionality and features of cloud services, it is more and more mind-boggling for the cloud users to find a trustworthy provider. Cloud users need to have confidence in cloud providers to migrate their critical data to cloud computing. There must be some means to determine reliability of service providers so that users can choose services with the assurance that the provider will not act malignantly. An effort has been made in this paper to formulate a hybrid model to calculate the trustworthiness of service providers. Cloud services are evaluated and trust value is calculated based on compliance and reputation. Service logs based compliance reflects dynamic trust. The reputation has been computed from collective user feedback. Feedback rating is the view of each user about the invoked services. The discovered services that fulfill the user requirements are ranked based on their trust values and top-k cloud services are recommended to the user. The proposed approach is efficient and considerably improves service-selection process in cloud applications.     

Beyond IN and UPT-a personal communications support system based onTMN concepts

The vision for future telecommunications is often described by the slogan “information at any time, at any place, in any form”, driven by both society's increasing demand for “universal connectivity” and the technological progress in the area of mobile computing and personal communications. In order to realize this vision, the emerging concept of personal communications support (PCS), which includes support for personal mobility, service personalization, and advanced service interoperability, is becoming increasingly important since it allows users to configure their communications environment in accordance with their individual needs, thereby providing them with controlled access to telecommunication services, regardless of their current location, terminal and network capabilities. This paper provides an overview of a personal communications support system (PCSS). The PCSS represents a platform providing advanced PCS capabilities in a uniform way to numerous communication applications in distributed multimedia environments. From a functional perspective, the PCSS provides enhanced intelligent network (IN) and universal personal telecommunication (UPT) capabilities with respect to user addressing (based on logical names instead of numbers) and advanced user control capabilities. From a design perspective, the centralistic IN/UPT approach to the realization of service logic has been replaced by a highly distributable, object-oriented approach based on X.500/X.700/telecommunications management network (TMN) concepts. This paper addresses the basic aspects of the PCSS, including design criteria, system architecture, supported applications, and evolution issues     

一种基于协同过滤的网格门户推荐模型

随着网格技术的不断发展,作为网格资源管理接口的网格门户也迅速发展起来。访问网格门户的用户数和门户管理的资源数也越来越多。为了解决网格门户系统资源管理信息规模过载、服务器大规模查询和处理资源负载较高、用户获取所需资源的满意度较低等问题,该文通过分析网格门户的主要功能和特点,在结合现有协同过滤推荐算法并改进的基础上,提出了基于协同过滤的网格门户推荐模型。推荐模型包括协同过滤交互模型、处理模型和展现模型。在设计模型的基础上提出了二次组合协同推荐算法并且进行了和现有算法的比较工作。实验表明:该文提出的推荐模型可以较好地实现网格门户的个性化协同推荐功能,并且可以保证个性化推荐的准确度和质量。