814 research outputs found

    NASA and the challenge of ISDN: The role of satellites in an ISDN world

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    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

    Digital encoding of black and white facsimile signals

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    As the costs of digital signal processing and memory hardware are decreasing each year compared to those of transmission, it is increasingly economical to apply sophisticated source encoding techniques to reduce the transmission time for facsimile documents. With this intent, information lossy encoding schemes have been investigated in which the encoder is divided into two stages. Firstly, preprocessing, which removes redundant information from the original documents, and secondly, actual encoding of the preprocessed documents. [Continues.

    Design mobile satellite system architecture as an integral part of the cellular access digital network

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    The Cellular Access Digital Network (CADN) is the access vehicle through which cellular technology is brought into the mainstream of the evolving integrated telecommunications network. Beyond the integrated end-to-end digital access and per call network services provisioning of the Integrated Services Digital Network (ISDN), the CADN engenders the added capability of mobility freedom via wireless access. One key element of the CADN network architecture is the standard user to network interface that is independent of RF transmission technology. Since the Mobile Satellite System (MSS) is envisioned to not only complement but also enhance the capabilities of the terrestrial cellular telecommunications network, compatibility and interoperability between terrestrial cellular and mobile satellite systems are vitally important to provide an integrated moving telecommunications network of the future. From a network standpoint, there exist very strong commonalities between the terrestrial cellular system and the mobile satellite system. Therefore, the MSS architecture should be designed as an integral part of the CADN. This paper describes the concept of the CADN, the functional architecture of the MSS, and the user-network interface signaling protocols

    Using IEEE 802.15.4/ZigBee in audio applications

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    Most of the current uses for ZigBee and IEEE 802.15.4 focus on control applications. However, there are other areas that will benefit from the standardisation, low cost and possibly low power of ZigBee/IEEE 802.15.4. This paper focuses on the use of ZigBee/IEEE802.15.4 for audio applications. We will discuss the advantages and theoretical limits of ZigBee/IEEE 802.15.4 for this kind of applications. We will then present a design that we used as starting point to develop applications related to the transfer of audio data

    On the proposed integrated services digital network

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    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

    Automatic database acquisition software for ISDN PC cards and analogue boards

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    This paper describes an application for automatic speechdatabases acquisition (ADA) developed by the authors in the framework of the EC Telematics Project SpeechDat II. The software is able to work with standard inexpensive PC cards for ISDN lines, as well as Dialogic Boards for analogue telephone lines. Both program versions share a common file format and configuration. Other important characteristics of the recording software are its simple set-up, a fast and flexible configuration of the recording session, the real-time monitoring of calls and disk space, and its proven robustness.Peer ReviewedPostprint (published version
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