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Communications Magazine, IEEE

Issue 6 • Date June 2000

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Displaying Results 1 - 19 of 19
  • Practical wireless data modem design [Book Review]

    Page(s): 42 - 46
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    Freely Available from IEEE
  • Satellite communication systems [Book Review]

    Page(s): 46 - 50
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    Freely Available from IEEE
  • Robust modulation methods and smart antennas in wireless communications [Book Review]

    Page(s): 50 - 52
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    Freely Available from IEEE
  • Intelligent networks in the new millennium [Guest Editorial]

    Page(s): 82 - 84
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    Freely Available from IEEE
  • Evolutionary trends in intelligent networks

    Page(s): 86 - 93
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    A number of groups are currently developing technologies aimed at evolving and enhancing the capabilities of intelligent networks. In this article we discuss three of these initiatives: PINT, Parlay, and IN/CORBA interworking. The IETF PINT work addresses how Internet applications can request and enrich telecommunications services. The Parlay consortium is specifying an object-oriented service control API that facilitates the access, control, and configuration of IN services by enterprise IT systems. The OMG's IN/CORBA interworking specification enables CORBA-based systems to interwork with existing IN infrastructure, thereby promoting the adoption of CORBA for the realization of IN functional entities. We address how all three of these technologies could be deployed together in order to provide a basis for a more flexible and open IN architecture. We also identify a number of common trends and potential pitfalls highlighted by current work on the evolution of IN. View full abstract»

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  • The HALO networkTM

    Page(s): 142 - 148
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    The High Altitude Long Operation NetworkTM is a broadband wireless metropolitan area network, with a star topology, whose solitary hub is located in the atmosphere above the service area at an altitude higher than commercial airline traffic. The HALO/Proteus airplane is the central node of this network. It will fly at altitudes higher than 51,000 ft. The signal footprint of the network, its “Cone of Commerce”, will have a diameter on the scale of 100 km. The initial capacity of the network will be on the scale of 10 Gb/s, with growth beyond 100 Gb/s. The network will serve the communications needs of each subscriber with bit rates in the multimegabit per second range. A variety of spectrum bands licensed by the FCC for commercial wireless services could provide the needed millimeter wavelength carrier bandwidth. An attractive choice for the subscriber links is the LMDS band. The airplane's fuselage can house switching circuitry and fast digital network functions. An MMW antenna array and its related components will be located in a pod suspended below the aircraft fuselage. The antenna array will produce many beams, typically more than 100. Adjacent beams will be separated in frequency. Electronic beamforming techniques can be used to stabilize the beams on the ground, as the airplane flies within its station keeping volume. For the alternative of aircraft-fixed beams, the beams will traverse over a user location, while the airplane maintains station overhead, and the virtual path will be changed to accomplish the beam-to-beam handoff. For each isolated city to be served, a fleet of three aircraft will be operated in shifts to achieve around-the-clock service. In deployments where multiple cities will be served from a common primary flight base, the fleet will be sized for allocating, on average, two aircraft per city to be served. Flight operational tactics will be steadily evolved and refined to achieve continuous presence of the node above each city. Many services will be provided, including but not limited to T1 access, ISDN access, Web browsing, high-resolution videoconferencing, large file transfers, and Ethernet LAN bridging View full abstract»

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  • Satellite Internet services using DVB/MPEG-2 and multicast Web caching

    Page(s): 156 - 161
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    Communication satellites can be used to broadcast large volumes of data directly to extensive user groups. With the latest generation of high-powered direct broadcast satellites and the changing traffic and usage patterns in the Internet, new ways of using satellites for delivering data directly to the end user have become viable alternatives to terrestrial point-to-point networks. In this article the software architecture of a distributed system, which has been successfully implemented and which supports online and offline interactive multimedia services, is presented. It is based on a method of carrying Internet datagrams over DVB/MPEG-2 transport systems, intended for digital television. It relies on a configuration using a broadband forward channel and a separate, usually narrowband, return channel. The forward link is usually provided by a geostationary satellite, whereas the return channel uses a different network technology, such as dialup connection, a direct Ku-band return link, a LEO satellite network, or an LMDS local distribution system. A generic multicast system is presented which exploits the inherent capabilities of satellites to reach a large number of customers. The reliable multicast strategy chosen is shown to handle multiple applications, each with different reliability and timing requirements View full abstract»

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  • LMDS systems and their application

    Page(s): 150 - 154
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    Local multipoint distribution systems (LMDS) represent a new radio-based access technology with cellular architecture offering flexible high-capacity connections to private users and organizations. The systems employ a point-to-multipoint broadcast downlink with a total capacity of 36-38 Mb/s per transport stream, giving high flexibility for inclusion of any type of data. The interactive channel, being a point-to-point connection, may employ different technologies depending on availability and user demand for capacity. This capacity may basically range from a few kilobits per second up to at least 25.6 Mb/s. LMDS performance relative to other broadband access technologies is discussed. A major remaining development task is the establishment and verification of methods for coverage of normally shielded areas. The availability of cheap repeaters and possibly reflectors for increased coverage is a must, which will significantly improve coverage. The LMDS technology, now in its first stage of implementation, is expected to enhance development of broadband services such as e-commerce and tele-teaching View full abstract»

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  • Dynamic resource allocation for quality of service on a PON with home networks

    Page(s): 184 - 190
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    Earlier efforts on optical access concentrated on the design of PONs for the collection and distribution portion of the access network. A possible evolution scenario for these types of access networks could be the SuperPON system. The SuperPON system exploits all possible upgrades of an FSAN APON system. In these networks the optical hardware is very simple, but a media access control protocol is needed for upstream traffic control. Even so, the role of communications is already well established in the office environment, thanks to networking innovations such as the Ethernet LAN. With the development of cheap, affordable broadband communications and the increasing complexity of consumer goods, it seems natural to extend the network into homes. As home area network application ever increases, we consider connectivity between the access network and the home network, which generates multiple traffic, in order to design a MAC protocol over the SuperPON access network with home networks. Global FIFO is quite simple, and allows dynamic upstream bandwidth allocation on the basis of a request-and-permit mechanism on the APON architecture. It has good bandwidth efficiency; however, being cell-based, it does not consider multiple traffic types from home networks. In this article we describe and analyze a new dynamic MAC resource allocation algorithm called multiple queue-FIFO that can achieve good performance under the SuperPON access network in the home network environment View full abstract»

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  • Evolution of optical transport technologies: from SONET/SDH to WDM

    Page(s): 164 - 172
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    It took roughly 10 years for the transport network industry to migrate from PDH to SONET. As this technology swap comes to an end, WDM technology is dawning, promising to revolutionize the network industry, with the possibility of transport bit rates above 10 Gb/s as well as transparency to signal encodings. However, a new wave of equipment upgrade is unlikely to happen as current SONET equipment is just beginning to pay off for its large investment. Thus, in years to come, SONET technology, the current standard for optical fiber access, will have to make room for WDM technology in a gradual way. On its part, WDM equipment must be developed to be backward compatible with SONET technology. This article discusses the requirements and issues involved in making WDM technology interoperable with SONET legacy equipment, as well as the evolution path toward a transparent optical transport network View full abstract»

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  • On joint protection/restoration in IP-centric DWDM based optical transport networks

    Page(s): 174 - 183
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    Previous advances in WDM technology are now beginning to shift the focus more toward optical networking and network-level issues. Providing survivability at the optical layer is inherently attractive, but whether it makes practical sense, given similar mechanisms that are already available at the higher layers, poses serious challenges and raises many questions. Today's core network architecture model has functional overlap among its layers, contains outdated functionality, and is too slow to scale. If IP can be mapped directly onto the WDM layer, some of the unnecessary network layers can be eliminated, opening up new possibilities for developing a simple and integrated-protection/restoration scheme that can be coordinated at both the IP and WDM layers. This article presents an overview of existing optical protection/restoration schemes. Then we present a novel mesh-based hybrid optical protection scheme that utilizes multifiber physical links along with a hierarchical OXC structure. An overview of the envisioned IP-centric DWDM-based optical data network architecture is then presented. The basis of how to implement a more direct IP standard-based approach for closer and efficient IP-WDM integration is also discussed. Finally, we articulate a view of how to provide a joint protection/restoration scheme that is coordinated at both the IP and WDM layers View full abstract»

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  • The future of the intelligent network

    Page(s): 100 - 106
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    This article examines the role the intelligent network (IN) can play as carriers move to next-generation networks. It discusses possible transition scenarios and examines how the IN could interwork with the Internet and packet-based networks to produce new hybrid services. The article presents a view of a fully converged network, and concludes that IN will continue have a vital role in voice and data services View full abstract»

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  • Satellite onboard processing for multimedia applications

    Page(s): 134 - 140
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    For future multimedia applications, satellites might play an important role. For broadcast applications satellites are ideally suited to illuminate a large geographical area. However, multimedia applications are interactive, and are therefore a combination of a broadcast mission and a multipoint-to-point mission. The natural question is, can a satellite system compete with the capacity provided by terrestrial cable networks? If the answer is positive, and it shown in this article that it is, a second question arises: what new developments are required to migrate from the state-of-the art satellite technology to such advanced concepts? Taking the example of the European Space Agency's activities in this field, an overview of the required building blocks which make up a complete multimedia communication satellite system are described. Based on this technological overview a discussion of the systems developed by European space industries with support from the European Space Agency is given View full abstract»

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  • Using TINA concepts for IN evolution

    Page(s): 94 - 99
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    This article proposes solutions that use TINA concepts for the future evolution of IN. It focuses on the specific need to provide a software architecture for the IN service control function which controls the transport network through INAP. After giving an overview of the TINA architecture, the article examines how it can be applied to IN. Several aspects are considered, such as architectural modeling, application of software technology and methodology, and definition of sets of standard open interfaces. The article concludes with a view on related activities in industrial fora View full abstract»

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  • A survey of future broadband multimedia satellite systems, issues and trends

    Page(s): 128 - 133
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    The demand for advanced information services is growing in terms of both the number of users and the services to be supported. Voice and low-rate data services are insufficient for users in a world where high-speed World Wide Web access is taken for granted. The trend is toward global information networks offering flexible multimedia information services to users on demand, anywhere, anytime. Potential services include video on demand, interactive video, fast Internet access, telemedicine, tele-education, and large file transfer. The need to support bandwidth-intensive multimedia services places new and challenging demands on satellite systems and networks. Flexibility, efficiency, mobility, and the ability to guarantee end-to-end quality of service are at a premium View full abstract»

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  • Mobile agent and CORBA technologies in the broadband intelligent network

    Page(s): 116 - 124
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    This article presents an IN architecture that is based on distributed object and mobile agent technologies. It deviates from traditional IN in two prominent ways: first, by substituting message-based protocols with a CORBA distributed processing environment. The new communications infrastructure not only serves to convey IN flows, but also functions as a potent unifying location-transparent layer. Second, the new architecture makes heavy use of mobile agent technology. Service logic programs are implemented as mobile agents, and are thus not constrained to control the switch's operations remotely from a central location. Instead, they can migrate and control its operations locally. The infrastructure elements of the architecture exploit this ability of service logic programs by cloning them and dragging their clones to the appropriate locations in response to excess processing or signaling load. The architecture is in this way self-balancing, in contrast to the centralized nature of traditional IN. A prototype implementation is presented along with a service creation framework that enables the IN service designer to disregard environment-related issues and concentrate on the IN logic of the services per se View full abstract»

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  • IN services for converged (Internet) telephony

    Page(s): 108 - 115
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    Given the convergence of the PSTN and IP-based networks, it would be advantageous to transparently support access to the existing installed base of intelligent network services from packet endpoints, while simultaneously providing newer, more advanced services to said endpoints from within the IN infrastructure. In this article we describe the INSeCT (IN Services for Converged [Internet] Telephony) prototype, aimed at achieving these very goals in networks using H.323. It presents background material on VoIP and IN, then focuses on the prototype implementation View full abstract»

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Aims & Scope

IEEE Communications Magazine covers all areas of communications such as lightwave telecommunications, high-speed data communications, personal communications systems (PCS), ISDN, and more.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Sean Moore
Centripetal Networks