Applications of satellite technology to broadband ISDN networks

Two satellite architectures for delivering broadband integrated services digital network (B-ISDN) service are evaluated. The first is assumed integral to an existing terrestrial network, and provides complementary services such as interconnects to remote nodes as well as high-rate multicast and broadcast service. The interconnects are at a 155 Mbs rate and are shown as being met with a nonregenerative multibeam satellite having 10-1.5 degree spots. The second satellite architecture focuses on providing private B-ISDN networks as well as acting as a gateway to the public network. This is conceived as being provided by a regenerative multibeam satellite with on-board ATM (asynchronous transfer mode) processing payload. With up to 800 Mbs offered, higher satellite EIRP is required. This is accomplished with 12-0.4 degree hopping beams, covering a total of 110 dwell positions. It is estimated the space segment capital cost for architecture one would be about $190M whereas the second architecture would be about$250M. The net user cost is given for a variety of scenarios, but the cost for 155 Mbs services is shown to be about $15-22/minute for 25 percent system utilization

Advanced Satellite Research Project: SCAR Research Database. Bibliographic analysis

The literature search was provided to locate and analyze the most recent literature that was relevant to the research. This was done by cross-relating books, articles, monographs, and journals that relate to the following topics: (1) Experimental Systems - Advanced Communications Technology Satellite (ACTS), and (2) Integrated System Digital Network (ISDN) and Advance Communication Techniques (ISDN and satellites, ISDN standards, broadband ISDN, flame relay and switching, computer networks and satellites, satellite orbits and technology, satellite transmission quality, and network configuration). Bibliographic essay on literature citations and articles reviewed during the literature search task is provided

Future benefits and applications of intelligent on-board processing to VSAT services

The trends and roles of VSAT services in the year 2010 time frame are examined based on an overall network and service model for that period. An estimate of the VSAT traffic is then made and the service and general network requirements are identified. In order to accommodate these traffic needs, four satellite VSAT architectures based on the use of fixed or scanning multibeam antennas in conjunction with IF switching or onboard regeneration and baseband processing are suggested. The performance of each of these architectures is assessed and the key enabling technologies are identified

Large-Scale Client/Server Migration Methodology

The purpose of this dissertation is to explain how to migrate a medium-sized or large company to client/server computing. It draws heavily on the recent IBM Boca Raton migration experience. The client/server computing model is introduced and related, by a Business Reengineering Model, to the major trends that are affecting most businesses today, including business process reengineering, empowered teams, and quality management. A recommended information technology strategy is presented. A business case development approach, necessary to justify the large expenditures required for a client/server migration, is discussed. A five-phase migration management methodology is presented to explain how a business can be transformed from mid-range or mainframe-centric computing to client/server computing. Requirements definition, selection methodology, and development alternatives for client/server applications are presented. Applications are broadly categorized for use by individuals (personal applications) or teams. Client systems, server systems, and network infrastructures are described along with discussions of requirements definition, selection, installation, and support. The issues of user communication, education, and support with respect to a large client/server infrastructure are explored. Measurements for evaluation of a client/server computing environment are discussed with actual results achieved at the IBM Boca Raton site during the 1994 migration. The dissertation concludes with critical success factors for client/server computing investments and perspectives regarding future technology in each major area

Virtual LANs and directory enabled networking

Lähiverkot ja virtuaalilähiverkot ovat kehittyneet valtavasti viime vuosien aikana. Lähiverkot ovat yleistyneet, mutta samalla uudet vaatimukset ja ominaisuudet ovat tehneet lähiverkkoympäristöstä entistä monimutkaisemman. Palveluntarjoajille tämä on mahdollisuus, koska niillä on riittävä asiantuntemus. Tämän avulla ne voivat tarjota lähiverkkoja ja virtuaalilähiverkkoja palveluna, jolloin niiden asiakkaat voivat keskittyä omaan liiketoimintaansa. Kehittyneet lähiverkot tarjoavat monia ominaisuuksia kuten autentikointia autorisointia ja priorisointia, mutta näiden ominaisuuksien pitää olla yhtenäisesti ja valmistajariippumattomasti hallittavissa Ns. directory enabled networking (DEN) on uusi ja lupaava lähestymistapa sekä verkon aktiivilaitteiden että verkon tarjoamien palveluiden hallintaa varten. Directory enabled networking ottaa myös kantaa palvelutasosopimuksiin (service level agreement), jotka ovat erittäin tärkeitä palveluntarjoajaympäristössä. Seuraavan sukupolven verkko voidaan rakentaa DEN-ominaisuuksien avulla

IP and ATM integration: A New paradigm in multi-service internetworking

ATM is a widespread technology adopted by many to support advanced data communication, in particular efficient Internet services provision. The expected challenges of multimedia communication together with the increasing massive utilization of IP-based applications urgently require redesign of networking solutions in terms of both new functionalities and enhanced performance. However, the networking context is affected by so many changes, and to some extent chaotic growth, that any approach based on a structured and complex top-down architecture is unlikely to be applicable. Instead, an approach based on finding out the best match between realistic service requirements and the pragmatic, intelligent use of technical opportunities made available by the product market seems more appropriate. By following this approach, innovations and improvements can be introduced at different times, not necessarily complying with each other according to a coherent overall design. With the aim of pursuing feasible innovations in the different networking aspects, we look at both IP and ATM internetworking in order to investigating a few of the most crucial topics/ issues related to the IP and ATM integration perspective. This research would also address various means of internetworking the Internet Protocol (IP) and Asynchronous Transfer Mode (ATM) with an objective of identifying the best possible means of delivering Quality of Service (QoS) requirements for multi-service applications, exploiting the meritorious features that IP and ATM have to offer. Although IP and ATM often have been viewed as competitors, their complementary strengths and limitations from a natural alliance that combines the best aspects of both the technologies. For instance, one limitation of ATM networks has been the relatively large gap between the speed of the network paths and the control operations needed to configure those data paths to meet changing user needs. IP\u27s greatest strength, on the other hand, is the inherent flexibility and its capacity to adapt rapidly to changing conditions. These complementary strengths and limitations make it natural to combine IP with ATM to obtain the best that each has to offer. Over time many models and architectures have evolved for IP/ATM internetworking and they have impacted the fundamental thinking in internetworking IP and ATM. These technologies, architectures, models and implementations will be reviewed in greater detail in addressing possible issues in integrating these architectures s in a multi-service, enterprise network. The objective being to make recommendations as to the best means of interworking the two in exploiting the salient features of one another to provide a faster, reliable, scalable, robust, QoS aware network in the most economical manner. How IP will be carried over ATM when a commercial worldwide ATM network is deployed is not addressed and the details of such a network still remain in a state of flux to specify anything concrete. Our research findings culminated with a strong recommendation that the best model to adopt, in light of the impending integrated service requirements of future multi-service environments, is an ATM core with IP at the edges to realize the best of both technologies in delivering QoS guarantees in a seamless manner to any node in the enterprise

Performance, models and topologies of common channel signalling system number seven.

Thesis (M.Sc.Eng.)-University of Durban-Westville, 1998.An Intelligent Network (IN) can be visualised as a central computer interconnected to the telecommunication network that allows the creation and deployment of services as consumer demand arises. Messages or information are transferred between the central processor and exchanges by a standardised form of signalling, known as Common Channel Signalling System Number Seven (CCS7). The thesis focuses on CCS7 performance, models and topologies. A requirement of the research entails the study of the CCS7 performance parameters: signalling delays and signalling network dependability. Signalling delays may be comprised of signalling message transfer delays within the message transfer part and queueing delays. Signalling network dependability usually include availability, reliability, maintainability and network robustness. For the purpose of modelling, the decomposition of the CCS7 message transfer part into subsystems is essential. A generic model for the message transfer part was used to implement certain functionalities of CCS7 in OPNET. OPNET (Optimised Network Engineering Tools) is a comprehensive engineering system capable of simulating large communication networks with detailed protocol modelling and performance analysis. The simulation software (OPNET) and performance parameters were used to analyse CCS7 networks resulting in the selection of a particular topology for a given region. The network structures analysed include the mesh topology, standard quad topology, hierarchical topology and Telstra's new topology. It was found that the mesh structure had the best simulated and availability/reliability results but was impractical for large networks due to the cost implications. This cost factor led to the selection of a hierarchical signalling system for Kwa-Zulu Natal