NGN业务平台安全性研究

由于下一代网络（NGN）业务平台面向以分组为基础的网络开展业务，同时又是开放的，所以有很多安全问题需要解决。文章从开放业务接口及业务开展两方面对NGN业务平台的安全性进行了探讨，认为：对开放接口的安全性问题。可以通过增加业务接入网关和业务管理平台两个设备解决，其中业务接入网关给开放业务接口增加的安全特性包括身份认证、授权、审计、加密、完整性保护等；对业务开展的安全性问题，可以通过发给用户数字证书、部署防火墙和入侵检测系统、进行负荷量控制、对用户属地进行管理、实时显示用户接入IP地址等手段解决。     

Heterogeneous Networks to Support User Needs with Major Challenges for New Wideband Access Systems

Third generation mobile radio systems are currently being deployed in different regions of the world. Future systems beyond the third generation are already under discussion in international bodies and forums such as ITU, WWRF and R&D programs of the European Union and in other regions. These systems will determine the research and standardization activities in mobile and wireless communication in the next years. Based on the experience from the third generation future systems will be developed mainly from the user perspective with respect to potential services and applications including traffic demands. This is directly related to the paradigm shifts from the first generation to systems beyond third generation. International bodies are already discussing basic system requirements. The basic system architecture of heterogeneous networks with different complementing access systems is from the today's perspective the most economic approach for systems beyond 3G to satisfy user and operator needs for reasonable cost. Such system architectures enable the deployment of system capacity according to the traffic requirements with the user experience ``Optimally Connected, Anywhere and Anytime' with seamless service provision between different access systems. New radio interface components with high data rate as additional components of systems beyond 3G are being proposed in international bodies. Key issues of such systems are coverage due to reduced range and the huge spectrum demand. In this paper the international context, the user perspective, revenue and traffic expectations are presented. This results in the basic system requirements and the potential system architecture of heterogeneous networks. Major challenges for the new wideband radio interfaces are the impact on range and spectrum demand. Basic investigations are presented on these issues to critically review requirements on future systems.     

Roaming and service management in public wireless networks using an innovative policy management architecture

Nowadays, public wireless local area networks (WLANs), commonly called hotspots, are being largely deployed by WISPs (Wireless Internet Service Providers) as a means of offering ubiquitous Internet access to their customers. Although a substantial number of solutions have been proposed to improve security, mobility and quality of service on the wireless area, access network management which is mandatory remains a very significant concern. This paper describes RSM‐WISP, a new management architecture designed for WISPs to facilitate the implementation and management of the services they offer at the access side of the WLAN, and to manage roaming contracts between WISPs. Our architecture is based upon the policy‐based management principles as introduced by the IETF, combined with more intelligence at the network edge. RSM‐WISP adopts an architecture that is composed of two elements: a WISP management center (MC) that deploys policies and monitors all the WLANs, and a programmable access router (CPE) located in each WLAN. The CPE ensures service enforcement, service differentiation (access to different service levels) and guarantee, user access management, and dynamic WLAN adaptation according to the user's SLA (service level agreement). It also permits automatic service updates according to the user's requirements. Concerning roaming management, this is achieved on the CPE through multiple service provider support capabilities. This approach provides WISPs with a simple, flexible and scalable solution that allows easy service deployment and management at the access. This management architecture has been implemented, tested and validated on the 6WINDGate routers. Copyright © 2005 John Wiley & Sons, Ltd.     

A lightweight convergent personal mobile service delivery approach based on phone book

Mobile phone users are demanding an efficient convergent communication approach for efficient communication and information sharing with their real life social circles. Unfortunately, the existing telecom services and the popular Internet services are not organically integrated to provide convenient convergent services. To overcome this issue, one of the promising convergent communication services considered by telecom carriers is RCS (Rich Communication Suite). However, existing issues, such as insufficient interoperability among different operators, shortage of terminals and heavy dependence on large‐scale IP multimedia subsystem (IMS) network deployment, mean that it will take time to implement RCS across worldwide networks and for it to become a service equally universal as voice and short message. Instead of a heavyweight RCS solution, in this paper, we propose a lightweight, quick deployment mobile phone book application system based on cloud computing without a fully deployed IP multimedia subsystem infrastructure, which seamlessly integrates traditional telecommunication services, instant messaging services, social networking services and automatic contact information management. Based on this, ‘Telco‐OTT’ service provision approach, telecom carriers can allow their subscribers to enjoy conveniently the rich convergent personal service experience quickly without a large initial investment. Thus, it is a low‐risk opportunity for telecom carriers to meet subscriber demand for advanced user‐centric convergent service features. Copyright © 2013 John Wiley & Sons, Ltd.     

The Concept of a Personal Distributed Environment for Wireless Service Delivery

Traditionally wireless service delivery has been restricted in scope to voice and text messaging and has been targeted at a single user device. Increasing interest is now being shown in ubiquitous delivery of services, including many forms of information and entertainment services, over a variety of wireless delivery mechanisms and to a collection of devices controlled by an individual user. These devices may be both local and remote to the user but their combination, and the services provided, form the user’s personal distributed environment (PDE). This paper reviews the concepts associated with a PDE and highlights some of the technical problems which require to be addressed in order to make such an environment a self-organising and attractive proposition from the user viewpoint. The paper defines the elements of a personal distributed environment and concentrates on the issues of personal access management and personal service management. It illustrates typical signalling exchanges required for the control of devices within the PDE and stresses the way in which the PDE may be attached to the core network. The paper will also illustrate a typical scenario in which a PDE might be deployed and will highlight the very important issues of security which must be incorporated in the overall PDE management.     

A Privacy Preserving Method Using Privacy Enhancing Techniques for Location Based Services

The move towards service-oriented architectures and the increasing usage of mobile devices to access such services are two of the major changes in modern computing. Information about the user, their location and their trajectory can provide additional context information to a service, leading to useful applications such as directing a user to the nearest bus stop and displaying which buses are due to arrive in the next minutes. While this type of information can be useful, when the offered services are trusted, it also introduces privacy issues relating to gathering of location information for non-trusted applications like location-based marketing or user behaviour profiling. Users can limit their location information provided to a service but these controls are simple, making it important for the user to understand how their location information is being used by services. This paper reviews some of the methods currently being proposed to reduce the impact of location tracking on user privacy, and presents a novel encryption method for preserving the location and trajectory path of a user using Privacy-Enhancing Technologies.     

网络出口转换技术研究

随着网络利用的普及,企事业单位都多数建有自己的网络,为满足不同的需求,接入了多个网络出口。如何解决网络服务与网络接入的关系,提高网络服务系统接口带宽和访问速度,是多网接入用户需要解决的问题,文中结合作者的工作经验,以Web网站作为服务对象,对上述问题进行分析和研究,其成果对多网用户有较好的借鉴。     

基于IMS的3G和WiMAX业务融合的探讨

利用WiMAX技术作为3G有效的接入补充方式,提出了3G和WiMAX业务融合的概念和实现目标,并给出了二者基于IMS的业务融合体系结构.认为实现业务融合的关键技术包括统一的会话管理、统一的用户标识、统一的用户数据及签约信息管理、统一的帐单服务以及统一的业务提供,分析了对应的解决方法.采用IMS作为业务层融合的网络平台,与3G核心网的演进以及基于IMS的固定、移动网络融合的下一代网络演进思路完全一致,对3G网络建设和规划具有很好的参考意义.     

Ethernet-based public communication services: challenge and opportunity

Enterprises and residential customers increasingly take advantage of more sophisticated applications and evolve their business models. At the same time service providers face declining revenues from existing connectivity services. SPs respond to these trends and start to offer highly customized, high-bandwidth network services that complement and interwork with their existing leased line, ATM, or frame relay offerings. Ethernet is quickly becoming the customer UNI of choice. Ethernet, being a packet-based technology, complements IP-based services such as content, voice, data, video, and additional value-added services over a high-speed access connection. Ethernet also provides a flexible high-speed connection to the SP network and eliminates access bottlenecks. Using Ethernet as the common access interface, providers can employ flexible transport services that enable additional value-added services at layer 3 and above. At the same time the rollout of Ethernet services also challenges the installed base, given that bandwidth per customer is usually much higher and additional attributes for tight SLAs apply. This calls for an updated approach to network deployment and rollout: networks need to be planned and built in a service-centric fashion. Starting with a brief look at the driving forces for Ethernet-based public communication services, this article identifies five generic services for Ethernet MANs/WANs and discusses related deployment issues of the different service options, such as the degree of customization, geographic reach and bandwidth profile of the service, as well as evolution aspects of the installed base.     

The (r)evolution of useful Web services

Internet services are improving all the time, becoming easier to use, more powerful, and faster. They have to improve in order to keep up with the tremendous increase in demand that is being placed on them. Some of the changes to the Web are incremental and evolutionary, slight improvements that accumulate over time to improve the user experience as a whole. Progress also comes with large sweeping discontinuous revolutionary change that totally reworks people's expectations of the way the network behaves. There is no reason to expect anything but continued pressure for continuous improvement of network services     

Mobility management incorporating fuzzy logic for heterogeneous aIP environment

The next generation in mobility management will enable different mobile networks to interoperate with each other to ensure terminal and personal mobility and global portability of network services. However, in order to ensure global mobility, the deployment and integration of both satellite and terrestrial components are necessary. This article is focused on issues related to mobility management in a future mobile communications system, in a scenario where a multisegment access network is integrated into an IP core network by exploiting the principles of Mobile IP. In particular, attention is given to the requirements for location, address, and handover management. In a heterogeneous environment, the need to perform handover between access networks imposes particular constraints on the type of information available to the terminal and network. In this case, consideration will need to be given to parameters other than radio characteristics, such as achievable quality of service and user preference. This article proposes a new approach to handover management by applying the fuzzy logic concept to a heterogeneous environment. The article concludes with a presentation of mobility management signaling protocols     

The common RRM approach to admission control for converged heterogeneous wireless networks

As the wireless environment becomes ever more populated and complex, individual networks offering single or restricted services will become ever more uncompetitive. Common radio resource management algorithms and strategies are used in heterogeneous or converged wireless networks to integrate multiple physical radio interfaces to support different levels of data rates, mobility, and traffic. Admission control in a common RRM environment is used to select the most appropriate wireless access based on service type, user preference, and network load. This is used to provide a balance between real-time and non-real-time traffic across the available access technologies. The development of common radio resource management strategies requires a suitable platform of coupled access networks and is the motivation behind the development of a converged wireless test platform. The tightly coupled platform supports voice and data call setup and delivery over UMTS and WLAN     

探索有线宽带与无线宽带的差异--用户体验影响要素分析

近年来,“带宽缩水”、“假宽带”等成为公众对有线宽带的吐槽焦点,而对手机上网用户评价尚可,两类宽带接入业务的用户体验差异较大。研究发现,除实际带宽外,用户期望、使用场景、业务种类、计费模式,甚至舆论导向都会对用户体验产生影响。建议运营企业综合考虑各项因素,提升网络质量的同时,避免过度宣传承诺,科学管理用户预期,有效改善用户感知。     

Three keys to developing and integrating telecommunications servicemanagement systems

With the deregulation of the telecommunication industry in Europe and the United States, communication and information services (e.g., multimedia entertainment services, educational services) are being increasingly delivered across value chains of network, service, and value-added service providers. The benefit of such interoperable services is the provision of “one-stop shopping” in which “tailored” services are delivered without their customers dealing with the multiplicity of underlying telecommunication services and network providers. The difficulty with such delivery chains is the complexity of managing these services across the different provider organizations (i.e., across both administrative and technological domains). These difficulties include achieving an understanding of business process across the organizations and the heterogeneity of the components to be (re)used to support these business processes in the organizations. This article examines three crucial elements in ensuring successful and flexible development of such service management systems-namely, a development process which is customized to support management system component development and component reuse; the development of business models capable of representing the underlying business processes for these systems; and an integration strategy designed to assist the flexible and timely cooperation of these management components both within a single organization (single administrative domain) as well as across organizations (multidomain)     

A next-generation service overlay architecture

The rapid evolution of next-generation networks and, in particular, fixed mobile convergence infrastructures raises the issue of providing personalized services adapted to the user’s context such as its device, access network, preferences, or quality of service (QoS) requirements. To design such value-added services, one solution consists in composing dynamically distributed service entities. In this paper, we propose a service overlay architecture in which a service level path is dynamically established to fulfill the user’s requirements. In order to meet this goal, two main issues have to be considered: service components discovery and service path management (i.e., setup, reconfiguration, release). The former issue is addressed based on a peer-to-peer approach in which QoS features are integrated in service lookup. For the latter issue, we rely on the Session Initiation Protocol to automate the setup of the service composition as well as its adaptation in case of perturbations (e.g., user switching device or service component failure).     

An agent‐based perspective to handover management in 4G networks

In 3G or earlier generation networks handovers are usually initiated and decided by the base station, on the basis of measurements of RSS or SNR received by the terminal, cell congestion, terminal speed etc. In 4G, due to the diversity of available radio access services, additional factors, for example user profile, application requirements, and terminal device capabilities, need also to be taken into account. We propose an agent‐based architecture that determines the timing and target network for handovers in a 4G network setting. The capabilities of the architecture are provided as a value‐added service on top of network operators' wireless access infrastructure. Network selection spans both wireless access and core routing services and is performed by user agents executing in the network side. In order to deal with trust issues we study the integration of the regulatory authority in the architecture. A performance study of the architecture's impact on handover latency is provided through a simulation system. Copyright © 2007 John Wiley & Sons, Ltd.     

Novel Radio Link Buffer Management Schemes for End-User Multi-class Traffic in High Speed Packet Access Networks

The requirement to provide multimedia services with QoS support in mobile networks has led to standardization and deployment of high speed data access technologies such as the High Speed Downlink Packet Access (HSDPA) system. HSDPA improves downlink packet data and multimedia services support in WCDMA-based cellular networks. As is the trend in emerging wireless access technologies, HSDPA supports end-user multi-class sessions comprising parallel flows with diverse Quality of Service (QoS) requirements, such as real-time (RT) voice or video streaming concurrent with non real-time (NRT) data service being transmitted to the same user, with differentiated queuing at the radio link interface. Hence, in this paper we present and evaluate novel radio link buffer management schemes for QoS control of multimedia traffic comprising concurrent RT and NRT flows in the same HSDPA end-user session. The new buffer management schemes—Enhanced Time Space Priority (E-TSP) and Dynamic Time Space Priority (D-TSP)—are designed to improve radio link and network resource utilization as well as optimize end-to-end QoS performance of both RT and NRT flows in the end-user session. Both schemes are based on a Time-Space Priority (TSP) queuing system, which provides joint delay and loss differentiation between the flows by queuing (partially) loss tolerant RT flow packets for higher transmission priority but with restricted access to the buffer space, whilst allowing unlimited access to the buffer space for delay-tolerant NRT flow but with queuing for lower transmission priority. Experiments by means of extensive system-level HSDPA simulations demonstrates that with the proposed TSP-based radio link buffer management schemes, significant end-to-end QoS performance gains accrue to end-user traffic with simultaneous RT and NRT flows, in addition to improved resource utilization in the radio access network.     

Data rides high on high-speed remote access

Internet and remote access services are growing by leaps and bounds, and major efforts are currently underway to provide greater bandwidth to the user by a multitude of access technologies, both wired and wireless. This article discusses the key access technologies currently being developed by vendors and deployed by service providers. It is expected that xDSL, cable data networks, and fixed and mobile wireless networks will be the hotbeds of tough competition, while direct satellite networks will hover over them with the potential to completely change the way the access networks are built. Irrespective of the ongoing debate on which technology would win or loose, in the world of real networks different access solutions will coexist, finding their own niches to meet the varying demands of performance and cost objectives for the end user