Broadband wireless access

This article reviews the technologies and potential markets, applications, and architectures for broadband wireless access. The emergence of wireless communications for cellular systems is presented, together with its projected future evolution to mobile wideband systems. The field of broadband access systems, services, and network architectures is also covered, and then systems for broadband wireless communications for indoor local area networks and outdoor public fixed access networks are discussed. Broadband wireless access systems are emerging as a new and growing area of telecommunications, since the ability to provide access without extensive installation of copper or fiber infrastructures make wireless technology well suited for broadband services. Finally, some of the key enabling technologies, such as adaptive antennas and video compression, and the future architectural directions of broadband wireless networks are presented     

A review of median filter systems for analog signal processing

This paper presents a review of existing analog implementations of the median and other ranked-order filter operations. The basic properties of median signal processing are first reviewed. Different analog median filter architectural approaches and implementations, introduced by several authors, are then discussed. These include filters based on analog delay lines and either nonlinear selection networks or ramp voltage generators. The Linear-Median Hybrid filter concept is presented and two examples of analog circuit implementations are given. Finally, a neural network approach is discussed.     

Cable access beyond the hype: on residential broadband dataservices over HFC networks

Current efforts in digital data transmission over hybrid fiber coaxial (HFC) networks will provide an efficient data transport mechanism for the “last mile” to residential users and will enable a very large number of services to the home. Provision of these services requires a complete end-to-end network architecture that provides an efficient connection between the server and the end user. Thus, it is necessary for the currently isolated HFC islands to gradually evolve into an efficient, highly connected, high-speed network. In this article, the authors review HFC networks and establish that they provide a more attractive and promising solution than the alternatives for “last mile” connectivity to the home, such as telephone connections. A list of broadband services are listed that are enabled by the high-speed data capabilities of HFC networks, and the necessary end-to-end infrastructure to support these applications is described, as well as possible evolution and migration paths for developing these end-to-end network architectures     

The emerging paradigm shift in storage system architectures

It is argued that currently dominant, large-scale storage architectures, built around central, shared storage systems with CPU-connected devices, are reaching economic and technological limitations and no longer meet performance, capacity, and transparency requirements. Models of historical scientific and technological paradigm shifts are reviewed, and the reasons why the authors believe such a paradigm shift is underway in storage system architectures are discussed. The requirements to be met, important technical problems being investigated, such as network-connected devices, use of storage hierarchies, and system management, and the characteristics of the emerging large-scale, distributed, storage-architecture paradigm are described and illustrated by actual implementations and by standardization work under way in the IEEE Storage System Standards Working Group     

Vehicular ad hoc networks (VANETS): status, results, and?challenges

Recent advances in hardware, software, and communication technologies are enabling the design and implementation of a whole range of different types of networks that are being deployed in various environments. One such network that has received a lot of interest in the last couple of years is the Vehicular Ad-Hoc Network (VANET). VANET has become an active area of research, standardization, and development because it has tremendous potential to improve vehicle and road safety, traffic efficiency, and convenience as well as comfort to both drivers and passengers. Recent research efforts have placed a strong emphasis on novel VANET design architectures and implementations. A?lot of VANET research work have focused on specific areas including routing, broadcasting, Quality of Service (QoS), and security. We survey some of the recent research results in these areas. We present a review of wireless access standards for VANETs, and describe some of the recent VANET trials and deployments in the US, Japan, and the European Union. In addition, we also briefly present some of the simulators currently available to VANET researchers for VANET simulations and we assess their benefits and limitations. Finally, we outline some of the VANET research challenges that still need to be addressed to enable the ubiquitous deployment and widespead adoption of scalable, reliable, robust, and secure VANET architectures, protocols, technologies, and services.     

Les progrès de la commutation électronique dans le monde

Following the review of the systems developed in industrialized countries (Part. I), the current trends of electronic switching are analysed. Structure basic principles are brought out: stored program control, standardization of languages, digital techniques and integrated networks, information interchange (signalling and data transmission), distribution network, data switching, message switching. The objectives are made accessible by the improvements in microelectronics (integrated circuits and microprocessors). The development of the various concepts and means leads to converging architectures and methods for the networks as well as for the systems (functional modularity, compatibilities, distributed control), to the standardization of new services, to the centralization of maintenance and to the dynamic management of the network.     

Emerging technologies for fiber network survivability

Reducing network protection costs, while maintaining an acceptable level of survivability, has become an important challenge for network planners and engineers. This article will review technology and architectures that may be used to implement cost effective survivable fiber networks for each transport layer, and discuss the interworking system between survivability mechanisms across different layers and associated open issues. Standards development, product availability and the current status of deployment will also be reviewed. The first section reviews a class of survivable fiber network architectures that has been deployed or is scheduled to be deployed. Next is a review of emerging technologies for these survivable architecture implementations. These emerging technologies include SONET, ATM, and passive optical technology. Finally the issue of multiple layer interworking on SONET/ATM networks is discussed     

Media access control for high-speed local area and metropolitanarea communications networks

The features, architectures, and principles of key media access control (MAC) schemes for high-speed LAN and MAN systems are categorized and reviewed. These architectures are related to the hierarchical structure of a telecommunications network. An overview is given of the MAC protocol operation of key local- and metropolitan-area network systems, as defined by standards committees, covering current methods as well as approaches for future broadband integrated services digital networks. Modeling and analysis techniques are then reviewed for key classes of relevant MAC schemes, including fixed-assignment time-division-multiaccess (TDMA) schemes; demand-assignment reservation schemes, involving, in particular, pure packet-switched, pure circuit-switched and hybrid-switched integrated-services demand-assignment TDMA and time-division-multiplexing structures; demand-assigned polling procedures; and random-access policies     

ISDN: a snapshot

A snapshot of the present status of ISDN (integrated services digital network) is presented in terms of standardization efforts, field trials and demonstrations, implementations and services, and equipment and devices. A review of opinions and controversies as well as future trends is also given. The authors emphasize the importance of the worldwide standardization effort and discuss the organizations that are responsible for establishing such standards. It is pointed out that, with the limitation and inflexibility of the narrowband ISDN and the broadband ISDN, issues for higher-rate services have become prominent. For broadband services, the problem is not merely increasing the speed of the operation. It affects the compatibility of switching technology, the workability of the local loop arrangement, the availability of rate adaption, and the efficiency of bandwidth utilization. Although some basic principles of narrowband ISDN can be carried to broadband ISDN, the technology is quite different. For example, the interconnection and transmission problems of video, HDTV, (high-definition television), and high-speed data are different from those of voice. Thus, the standard 64-kb/s B channel itself, the fundamental rate of ISDN transmission, appears inadequate for wideband services. At present, the solution is to establish the multiples of 64 kb/s for accommodation of broadband or higher rates     

Teleaction services: an overview

Many large industries are beginning to decide whether they will use simple, low-speed data communications. These low-speed services may be the first data services that most small business and residence customers buy because the market already needs them. As a group, they are called teleaction services. The term teleaction means "acting at a distance." The actions include reading or writing some information to remote locations, or possibly both. Instead of sending a person to set or read some information on a device, it is done remotely via a communications network. This form of data collection is especially useful when coupled with a computer system that could use the data to initiate action. Currently, some of these services have low market penetration. However, the market need for them is real, and potential users consistently express interest in them. The challenge is to be able to deliver them in a cost-effective way. The purpose of the article is to provide a review of these services. The author provides a classification and an overview of current and emerging services with an emphasis on the specific business aspects of each service and each market segment. Then, the business drivers are discussed from the perspectives of the end user, the service provider, and the communications carrier     

A high-performance end system architecture for real-time CORBA

Many application domains (e.g., avionics, telecommunications, and multimedia) require real-time guarantees from the underlying networks, operating systems, and middleware components to achieve their quality of service (QoS) requirements. In addition to providing end-to-end QoS guarantees, applications in these domains must be flexible and reusable. Requirements for flexibility and reusability motivate the use of object-oriented middleware like the Common Object Request Broker Architecture (CORBA). However, the performance of current CORBA implementations is not yet suited for hard real-time systems (e.g., avionics) and constrained latency systems (e.g., teleconferencing). This article describes the architectural features and optimizations required to develop real-time ORB end systems that can deliver end-to-end QoS guarantees to applications. While some operating systems, networks, and protocols now support real-time scheduling, they do not provide integrated solutions. The main thrust of this article is that advances in real-time distributed object computing can be achieved only by systematically pinpointing performance bottlenecks; optimizing the performance of networks, ORB end systems, common services, and applications; and simultaneously integrating techniques and tools that simplify application development     

Strategies for provisioning and operating VHE services inmulti-access networks

Providing advanced services over multi-access networks is a challenging issue for service providers as well as for network operators. This article presents a framework for provisioning virtual home environment services dealing with these issues. We evaluate ongoing standardization activities in this area, and propose strategies suitable for deployment, and operating associated systems and services     

Virtual private network services: scenarios, requirements and architectural constructs from a standardization perspective

This article describes scenarios, general requirements, and architectural constructs for the emerging category of services known as virtual private networks. According to the adopted reference models, the principal architectural choices in the service provider solution space and current VPN-related standardization initiatives are introduced.     

Home systems standards: achievements and challenges

"Home systems" is a new consumer products industry. The market potential is very large, although the market has been evolving very tenuously. What is certain is that consumer demographics favor more conveniences for busy families and devices that assist those with physical limitations. Products based on home systems technology will serve both of these market segments. A variety of consortia and authorized standards bodies have been writing specifications for residential networks to provide a communications infrastructure for home systems and connections to external networks. This strategy of defining an infrastructure to support a nascent market is unusual. However, it offers the opportunity to specify a network without backward compatibility constraints, so often a requirement when upgrading and standardizing existing networks. This article addresses the fundamental question: has the home systems industry been successful in writing and adopting standards that promote industry growth? In part, the emergence of the home systems industry is a work in progress. Nevertheless, important standards and consortia programs have been developed since the mid-1980s. Some of the prominent achievements in home networks are reviewed. This article concludes that a clean slate offered by an undeveloped market is an advantage to standards writers. However, there needs to be a strong impetus to enter a potentially thriving market in order to motivate the standards writers to target and complete their work expeditiously. Otherwise, the writers will invest too much time perfecting their work, rather than making pragmatic compromises     

Information infrastructures and multimedia communications:different approaches of the telephone, data, and radio/TV worlds

Information infrastructures and multimedia communications are necessary prerequisites for the future information society. Approaching the multimedia world of tomorrow, the telephone world, the data world, and the radio/TV world of today will overlap to a growing extent. This is true for utilization and technology as well as for market and competition. There will more likely be an application revolution; however, for networks-and partly for services and terminals, too-it has to be an evolution. Among others, ISDN and later ATM networks are expected to contribute to efficient information infrastructures and multimedia communications. The article discusses overall concepts for office, home, and travel; end-to-end solutions, including the intelligence and management needed (full-service and application-ready networks); and suitable standardization of architectures, building blocks, and platforms. For the transfer toward the information society, many political and legal problems have still to be solved on a national and international basis, in addition to technical and economical aspects. The immense upheaval, at least, asks for some common vision and some joint action through pragmatic cooperation of the parties involved     

IPTV Systems, Standards and Architectures: Part II - IPTV Services over IMS: Architecture and Standardization

This article presents an architecture to support IPTV services in an IMS-based NGN. The architecture extends the current IMS specification with the required functionality to meet additional requirements of IPTV services. The proposed architecture can be deployed by an IPTV provider over heterogeneous access networks (mobile, wireless, and fixed) as a part of standardized NGN solutions. After presenting an overview of the IPTV standardization activities in DVB, ITU-T, ETSI, ATIS, 3GPP, and OMA, this article focuses on the ETSI TISPAN IPTV standardization. IMS-based IPTV architectural functions and possible IPTV evolutionary steps are discussed, and then the article presents an implementation example.     

家庭网络标准及其研究计划

家庭网络处于不断发展的过程中，家电／IT行业与电信行业对于家庭网络的理解和发展思路也不一样，因此无论国际和国内都有很多从事家庭网络标准化的组织，标准不统一。中国正在制订家庭网络相关标准的组织主要有3个，分别是信息设备资源共享协同服务标准工作组（IGRS）、e家佳和中国通信标准化协会（CCSA），目前都已有了一些研究成果。为了提高中国在家庭网络领域自主创新的能力，进一步加快中国家庭网络的标准化进程，3个标准化组织应该打破行业壁垒，加强合作，实现优势互补，以合作共赢的态度研究中国自主的家庭网络标准。     

智能网标准概况

智能网可以为各个网络提供服务.本文介绍了我国在固定智能网、CAMEL、WIN和综合智能网方面的标准化工作,并介绍了一些标准的主要内容和标准之间的关系.     

Network of the future

Telecommunications networks of the future will exploit two new network architecture concepts that are currently being implemented, or soon will be. These are the Intelligent Network and ISDN, the Integrated Services Digital Network, which together will support a full range of voice, data, and image services that Information Age telecommunications users will demand. These new network architectures, operating synergistically with intelligence in terminal systems, will constitute a framework in which users and service providers will link together standardized functional components to create customized services. These components, along with interfaces and signaling protocols at the interfaces and within the network will result from continuing national and international standardization efforts. In the planning of these new architectures, a few major goals are of paramount importance: • the achievement of a flexible network structure in which functionality is distributed among the network components in a way which supports the timely and economic introduction of new services in response to user needs; • the establishment of industry standards at the interfaces between network elements such that service suppliers can choose among a set of available systems products in building their networks and avoid dependence on a small set of suppliers, • the development of standard user interfaces supporting signaling procedures which can provide the user with increased control of, and access to, services to satisfy his needs; Achievement of these goals will result in the realization of an Open Network Architecture. The ISDN and Intelligent Network architecture concepts are described in this paper.