442 research outputs found
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 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
NASA and the challenge of ISDN: The role of satellites in an ISDN world
To understand what role satellites may play in Integrated Services Digital Network (ISDN), it is necessary to understand the concept of ISDN, including key organizations involved, the current status of key standards recommendations, and domestic and international progress implementation of ISDN. Each of these areas are explained. A summary of the technical performance criteria for ISDN, current standards for satellites in ISDN, key players in the ISDN environment, and what steps can be taken to encourage application of satellites in ISDN are also covered
On the proposed integrated services digital network
The ultimate aim of this dissertation is neither to increase the state of the art in networking technology nor to predict the future structure of telecommunications networks. It is an attempt to raise the awareness of both the author and the reader as to the evolutionary forces driving vast changes in the telecommunications field. The impact of these changes will significantly alter the way we live and conduct business in the Information Age. For those involved with the communications field, the ability to make sound business decisions will require an in-depth knowledge of the technology and services that compose ISDN. Therefore this paper will explore the motivating forces, the potential services, and the technical components in the emerging Integrated Services Digital Network (ISDN). My interest in data communications was kindled at RIT and has continued in my work, both as a systems programmer in the telecommunications division at the Travelers Insurance Company and as a printing systems analyst for Xerox Corporation. This thesis has helped me answer both personal and professional questions about the future of telecommunications and to share this information with others
ISDN at NASA Lewis Research Center
An expository investigation of the potential impact of the Integrated Services Digital Network (ISDN) at NASA Lewis Research Center is described. To properly frame the subject, the paper contains a detailed survey of the components of Narrowband ISDN. The principles and objectives are presented as decreed by the Consultative Committee for International Telephone and Telegraph (CCITT). The various channel types are delineated and their associated service combinations are described. The subscriber-access network functions are explained pictorially via the ISDN reference configuration. A section on switching techniques is presented to enable the reader to understand the emergence of the concept of fast packet switching. This new technology is designed to operate over the high bandwidth, low error rate transmission media that characterizes the LeRC environment. A brief introduction to the next generation of networks is covered with sections on Broadband ISDM (B-ISDN), Asynchronous Transfer Mode (ATM), and Synchronous Optical Networks (SONET). Applications at LeRC are presented, first in terms of targets of opportunity, then in light of compatibility constraints. In-place pilot projects and testing are described that demonstrate actual usage at LeRC
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An Examination of the Evolution of Broadband Technologies in the UK
The aim of this thesis is to examine the reasons due to which Digital Subscriber Line (DSL) became the most widely used technology to deliver broadband connectivity in the United Kingdom (UK). The research examines the outcome starting with events in 1960s when broadband as it is defined today did not exist. The research shows that a combination of factors involving regulatory decisions, changing market conditions, and unexpected technological breakthroughs contributed to the current day mix of broadband technologies in the last mile access in the UK.
To interpret the events that have shaped the development, deployment, and adoption of broadband technologies in the UK, the thesis draws from various theoretical ideas related to Science and Technology Studies (STS) to understand and analyse the events. In order to discover and establish the historical context, the thesis employs original, unpublished interviews along with the extensive use of archival material and secondary sources. Influenced by some of the core ideas of social constructionist studies, this research combines concepts from economic studies of technological change along with themes involving maintenance of technology, path dependence, and the role of bandwagon effect.
These research threads are combined to understand the way development, deployment, and adoption of broadband technologies took place in the UK. The research is intended to contribute to the understanding of technology in a constantly changing regulatory and socio-economic environment and how it is shaped by multiple factors. The targeted readership is researchers, analysts, and decision makers working with broadband technology, telecommunications policy, and STS. Further research is suggested in the form of studies of wireless broadband technologies and the role of regulatory policies in the development of the UK communications market
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