Advanced IMS Multipoint Conference Management Using Web Services

The IMS conference control interfaces are still in an early stage of development, allowing only the creation of basic group communication services where the service definition and policy are either preconfigured or managed through proprietary mechanisms. The Web service abstraction for third-party service application development of those native interfaces, the OSA Parlay X multimedia conference Web service, inherits these limitations, therefore constraining the possibilities for advanced multipoint conferencing application deployment over the IMS platform. In order to address these deficiencies, the native IMS conference control interfaces need to be enhanced to provide a broader and finer-grained management environment, while maintaining high flexibility, scalability, and interoperability levels. This article describes the current IMS conferencing framework, at both the native and application-interfacing levels, analyzing its deficiencies and presenting how a deeper involvement of Web services would contribute to overcoming its limitations at both levels.     

A Study on the Use Intention of Long Term Evolution Mobile Service

The rapid development of ICT is bringing about a digital transformation. The digital transformation affects all areas, and ICT is at the center of many technologies. In particular, the importance of technical services for wireless communications is being increasingly emphasized. Thus, the qualities of technical services for wireless communications have effects not only on the companies who provide services but also on the consumers who receive them. As technologies develop, consumers want to receive more stable and higher quality services. In this regard, this study classified the qualities of LTE service into call quality, speed quality, and user support quality, investigated their influential factors on perceived usefulness, perceived ease of use, and playfulness, and analyzed their causal relationship with satisfaction and continuous use intention. As a result of analysis, all the hypotheses were accepted; except for the one that call quality will have effects on perceived usefulness (H1-1), except for the one that social influence will have effects on user satisfaction (H7-2), except for the one that customer membership will have effects on perceived usefulness (H8-1), except for the one that social influence will have effects on perceived usefulness (H8-2). The results of this study provided practical guidelines to service providers through the causal relationship analysis of various variables affecting LTE services satisfaction and constant services.     

Heading towards an advanced signalling system for multimedia,multiparty services in broadband ISDN

Introduction of the broadband integrated services digital network (B-ISDN) will enable network users to make use of advanced multimedia, multiparty services. With this aim in view, RACE II project R2044, MAGIC, is investigating long-term signalling requirements, architecture and protocols for B-ISDN. New service concepts are being developed in MAGIC which will provide more flexibility when compared to narrowband ISDN (N-ISDN). The service requirements and other signalling requirements, such as the separation between call and associated connections at the network-node interface, are used to determine the distribution of functions over the network. The signalling protocols which are used to exchange the signalling information are subsequently developed. These signalling protocols are simulated to prove the performance and the feasibility of call handling concepts     

5G邻近服务关键技术

随着移动通信网络的发展,邻近服务功能为提高用户服务质量提供了更大的实现空间,同时存在更大的挑战.本文结合当前3GPP中邻近服务功能的标准研究情况,主要描述了5G邻近服务的关键技术,介绍了基于邻近服务的授权和直接发现流程,并分析了不同邻近服务中继通信方式的技术特点和适用的应用场景,研究了尚待解决的问题,并从多个角度分析了...     

单片机在数字示波器设计中的应用

基于单片机处理的方式的数字示波器是以单片机为控制中心,通过对采样电路的控制进行波形实时采样、数据处理和存储显示。该方案系统规模较小,有一定的灵活性,成本低廉,但是受限于单片机速度,难以实现信号的实时处理和显示。文章描述了基于EDA技术实现等效采样,以及单片机实现LCD显示和键盘操作。虽然受条件和技术限制使所覆盖的频率要小于实际要求,但是在所允许的频率范围内,示波器的精确度均超过了实际要求。     

智能光网络的应用探讨

随着传输技术的不断进步和数据及互联网业务的迅猛发展,智能光网络的应用越来越广泛。智能光网络具有路由自动恢复、动态支持业务、网络可靠灵活等技术特点。智能光网络的网络结构采用网状组网方式,其控制平面采用分布式处理方式并与网络管理系统共同完成网络的控制与管理,智能光网络可以从现有骨干网络和城域核心网络进行引入。     

Customer service provisioning in intelligent networks

The author points out that despite the convenience of using functional components (FCs) as service building blocks, service provisioning in the intelligent network (IN) still presents major problems. He focuses on issues of responsiveness to customers. When customers are allowed to provision new IN services, it is necessary to consider whether the set of FCs can be directly used by customers without cause problems and whether the set of FCs of flexible enough to construct the services customers are likely to want. The author investigates customer service provisioning problems and flexibility in using the IN FCs, and proposes methods to support integrity control for service development. For concreteness, he focuses on the set of FCs defined in Bellcores's IN/1+ network     

Next generation multiservice VSAT networks

Very-small-aperture terminal (VSAT) satellite networks have so far been successful in the provision of specific communication services to geographically dispersed users. However, user demands are becoming more complex and VSAT networks are expected to provide a much wider range of services (voice, data and multimedia). This paper investigates how this service integration could be achieved and shows that performance improvements are possible if efficient multi-access protocols and speech compression with voice-activity-detection techniques are used. It also discusses the future role that VSATs could play in the provision of access to the integrated broadband communication network to remote users. It is shown that it could be possible to use VSATs for ATM service provision, but there are limitations on the system's performance from the satellite delay and limited link capacity     

Enabling hybrid services in emerging data networks

For a number of years, the network, software, and telecommunication industries have been working on a number of key technical issues dealing with the infrastructure support for hybrid services. From the end users' perspectives, hybrid services utilize various networks while hiding the underlying network technologies such as the wireless networks, phone system, and data networks. To this end, however, the data networks lack necessary power to support next-generation hybrid services. It is now generally understood that there is great value in creating a three-level network model with the middle level supporting a service platform that would contribute certain common services. Such a data network would provide the common services at its edges close to its points of presence (POPs) while maintaining control over all network components belonging to a specific network provider. It would interoperate with other networks to offer a uniform view and management of all hybrid services. This article describes the nature of the enhanced emerging networks and outlines the structure of a service platform that would support its functions     

True number portability and advanced call screening in a SIP-basedIP telephony system

Custom local area signaling service features offered in the PSTN have certain limitations due to the closed nature of PSTN network signaling. The adoption of telephony over IP (IP telephony) will enable a new paradigm of services and features that are not possible to implement in today's PSTN. This is especially the case for services that make use of personal, trusted information, which can be provided by a user's personal digital assistant. We demonstrate how personal information can be coupled with an IP telephony service to provide user-customized call handling by the network. In particular, we describe a demonstration architecture that includes Ethernet-attached phones running SIP, with an interface to synchronize with PDAs that supply personal information. The proposed architecture is quite flexible; it can support enhanced versions of the current PSTN and private branch exchange services, in addition to many new features and services. We describe true number portability and advanced call screening as examples of new services in a hybrid PSTN/IP telephony environment     

Universal digital portable radio communications

Providing voice and data communications to people away from their wireline telephones has become a major communication frontier. This frontier is being penetrated by evolving approaches to portable communications, e.g., cordless telephones, mobile radiotelephone, and radio paging. However, these approaches have many limitations; none can provide universal portable communications services. This paper discusses limitations of the evolving approaches and considers objectives and approaches for providing more universal digital portable communications as an integrated part of telephone exchange networks. These more universal communications could be accomplished by using demand-assigned radio links for the last thousand feet or so of telephone loops and sharing the remainder of the fixed distribution facilities. Fixed radio ports as integrated parts of telephone distribution networks could be placed throughout service regions. Efficient use of the radio spectrum could be insured by the planned reuse of radio frequencies throughout the regions. The severe multipath radio propagation environment within and around buildings that strongly influences the design of portable communications systems is described in the paper. System configurations and radio link techniques, that can provide reliable communications in the multipath environment, are discussed. Radio system calculations are illustrated for radio ports with 30-ft-high antennas in residential areas. The calculations indicate that radio link availability would be greater than 99 percent for 2000-ft port separations and 5-mW portable transmitters. Reuse of frequencies would require dividing the allocated frequency band into segments for use at adjacent ports. Calculations suggest that link availability in the cochannel interference environment would be greater than 99 percent, if 25 to 35 segments were used in residential areas.     

Use of policy management to achieve flexibility in the delivery of network-centric ICT solutions

Network-centric ICT solutions present significant challenges for telecommunications operators. Enterprise-scale customers want joined-up IT functionality combined with increased flexibility, improved control and predictable performance. However, ICT is much too dynamic and complex to deliver and support efficiently using current service management methods. To fully deliver against the vision, changes need to be made to the models that underpin the use of the technology. This paper explores the role that policy-based management has to play within an integrated IT and communications infrastructure. It argues that profitable ICT deployment and management will be dependent on policy-driven business systems that provide extensive automation and flexibility, providing a unified means of managing services to meet the needs of the user. To assess the practical benefits, details are also presented of a proof-of-concept demonstrator employing policy-based ICT service management within the context of on-demand IP-VPN access.     

下一代网络部署中的QoS策略

随着下一代网络(NGN)技术的逐步应用,电信运营商拥有了能够同时提供传统的电信级语音业务和基于IP的多媒体业务的统一平台。如何确保这个平台稳定运行,保障不同类型客户的通信质量,成为一个系统性的问题。针对NGN的网络体系结构和业务特点,从系统的角度出发,探讨了NGN建设中QoS(服务质量)保障的策略,从而实现网络上各类业务在端到端上的QoS保障     

下一代网络业务架构的探讨

随着网络技术的飞速发展,原有的网络已不能满足用户的需求。以软交换设备为核心,能够提供话音、视频、数据等多媒体综合业务,采用开放、标准的体系结构,能够提供丰富业务的下一代网络(NGN)应运而生,且一度成为人们关注的热点。文章通过对NGN业务演进策略的分析得出NGN业务架构应满足的性能要求,然后根据现有的各项NGN业务技术构建了NGN业务架构,实现了传统电信业务和Internet业务的融合。     

云计算环境下基于信任演化及集合的服务选择

针对云计算环境中服务节点的可信度参差不齐常导致用户很难获得高质量组合服务的问题,提出了一种基于信任生成树的云服务组织方法,将服务提供者与请求者的交互行为经演化后形成信任关系,使主体间可信程度达到相应级别,形成对外提供相似服务功能的云服务集合,将恶意、虚假的服务排除在信任生成树之外,使服务组合在可信场景中进行;在此基础上,采用了基于信息熵的度量策略来对服务间的信任关系进行评估,解决了现有研究中仅对可信参数进行简单加权分析的不足。实验分析表明,该方法能有效抑制云计算环境下恶意节点的欺诈行为并保护真实节点的合法利益,具有较好的服务选择质量。     

Dynamic composition of services for end-to-end information transport - [Service-oriented broadband wireless network architecture]

An increasing number of communication technologies in access and core segments of the network belonging to different providers and subject to different network design criteria are making networks complex and difficult to manage. In such networks it is also more difficult to guarantee requested levels of quality of service. Service oriented design can be the answer to problems facing the providers of services for information transport. In this article we propose an end-to-end service composition for information transport based on principles from service oriented architecture (i.e., dynamically composing transport services with characteristics matching the requirements of a given application). SOA principles are similar to those behind the division of labor, and therefore should give providers incentive to adopt them to make better use of resources and increase revenue. As we show, some SOA concepts are similar to concepts in the open systems interconnection reference model, with the key advantages of dynamism and flexibility. We discuss service oriented networks based on transport service composition across access and core segments, and describe access network selection for online gaming. In particular, we show how semantic technologies can be used for layer 2 queries and discuss the advantages of using knowledge bases over traditional approaches.     

Advanced communication technologies and services: Design configuration and stakeholder interests in Europe

Rapid “take-up” in the use of advanced telecommunication technologies and services involves co-ordination between private and public interests in establishing the environment for private investment in new equipment and services to upgrade the existing infrastructure. Alternative scenarios are possible for these developments in Europe. The outcome of this process will depend upon the interaction between public policies and private decisionmaking in several producer and user communities. This paper rejects the consensus view that market forces will suffice in coordinating demand and supply to achieve a socially desirable scenario for future developments. Decisions about the use of technologies and services for addressing social exclusion and redefining the concept of “universal service”, for enhancing the usability of complementary technologies, for establishing technical compatibility standards and for assuring privacy and security will have major impacts on the outcomes. Three configurations of suppliers—Insurgents, Incumbents and Virtual Community service providers—as well as key user groups are identified. The interactions amoung these groups and the content of private and regulatory decisions provide a foundation for several possible scenarios of future developments. Major differences in the opportunities for European producers and consumers exist depending on which of these scenarios is realised and the role of policy decisions in shaping the outcome.     

The common capability approach to new service development

A major challenge for any telecommunications company is how to improve time to market for new services and at the same time reduce costs and improve the customer experience. This paper shows how BT has analysed this problem and has set about addressing it. The result of the analysis was to propose the concept of reusable capabilities — a concept widely used in the manufacturing industry and now applied to complex telecommunications services to meet these challenging goals. BT carried out a functional decomposition of each service into elemental capabilities and to see if common elements could be found between each service. The results were somewhat surprising, with a very high correlation between the elemental service building blocks BT defined and the new services. BT is now launching services which use the first deployment of common capabilities laying the foundations for the rapid introduction of new services. The capability approach will gain increasing traction as the number of developed capabilities increases, which will lead to greater service flexibility, cost reduction, improved time to market and further improved customer experience.     

Privacy from Promises to Protection

Privacy issues are becoming more and more important especially since the cyber and the real world are converging up to certain extent when using mobile devices. Means that really protect privacy are still missing. The problem is, as soon as a user provides data to a service provider the user looses control over her data. The simple solution is not to provide any data but then many useful services, e.g. navigation applications, cannot be used. In order to solve this problem, we propose privacy guaranteeing execution containers (PGEC). Basically the concept is that the application obtains access to the user data in a specially protected and certified environment, the PGEC. PGECs enable applications to access private user data and guarantee that the user data is deleted as soon as the service is quit. The PGEC also restricts the communication between the application and the service provider to what is explicitly allowed by the service user. In addition to those means the PGEC also implements countermeasures against malicious attacks such as modified host systems and covert channel attacks, which might be misusing CPU load to signal data out of the PGEC. Thus, the PGEC guarantees a “one time use” of the provided private data.