Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 116-126). Also available via the Internet.

International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, California / The Edwards Digital Switch (EDS) is a digital communication system that provides advanced voice networking capabilities to the Edwards Test Range. The EDS is a member of a new family of all-digital switching systems that internally handle data in digital form. To accommodate analog voice and data circuits, conversions between analog and digital formats occur at the system interfaces. The EDS consists of six groups of configuration items: System-level control and monitoring is centralized in the Control and Display Subsystem. Workstations provide subsystem-level control and monitoring. The Central Switching Subsystem, as the primary interface with the range environment, provides system connectivity to radios, telephone circuits, and communications links to other facilities. It integrates the EDS with links to the Control Room Switching Subsystems. Each Control Room Switching Subsystem connects individual user stations within a Mission Control Room or other localized area. The user equipment element consists of a Subscriber Terminal Unit, Channel Expander, and interface panels for headsets, foot switches, and speakers. The Remote Radio Control Unit optimizes usage of available frequencies, allowing control of tunable radios from the Control and Display Subsystem. *The original name, Edwards Communication Switching System (ECSS) was changed to Edwards Digital Switch (EDS) in 1990. The Site Selection Unit facilitates the handover of voice communications between receiver sites when a long-range test is monitored. The system architecture is based on a central system-level control element, a central switch, multiple subsystem-level control elements, multiple subsystem switches, and end-equipment items that are interconnected through the switch network. The EDS combines multiple voice communications applications in a single system. The system is being expanded to integrate voice and data switching. Its major function is support of multiparty networked voice communications within Mission Control Rooms and between other test participants. Other voice functions are an intercom capability including both Direct Access (hot line) and Indirect Access (dial-up), subscriber loop connections to the base-level telephone exchange, and the Public Switched Network System. Digital interfaces allow integration of ciphertext data and Time Space Position Information data switching functions. A system based on the EDS design has also been installed by the Air Force at Eglin AFB. Engineering studies for systems that make use of the EDS design are currently underway by the Navy at China Lake and the Army at White Sands Missile Range. The EDS project office has actively pursued promising program management concepts such as: specifying nondevelopmental items, requiring industry standard interconnectivity and interoperability, and using a multiyear fixed-price requirements-type contract to encourage multiservice participation.

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This paper architecturally describes the switching portion of a digital communications system that is dedicated to conferencing. The basic ideas and methods of circuit switching and packet switching are introduced. The conferencing function is described, and some resulting design considerations are discussed. The architecture of the switch is then presented. Circuit switching techniques are used throughout the architecture of the switch, coupled with arithmetic processing to accomplish the conferencing function. The architecture is developed in such a way that it is expandable in all directions to meet a given set of requirements. The requirements include the number of users the system supports and the number of conference channels provided. The processing stages of the switch can be sized based on these requirements and the chosen component speeds. The basic timing of each stage is given to describe its operation and establish the critical delay paths. The resulting switching methods first introduced. The switch is also tested to see if it fits the criteria for being a distributed processing system. It is concluded that if the provision for dynamic reconfiguration is added, the switch fits the criteria. Finally, further topics of study are suggested.

This thesis is mainly a survey of optical devices used in optical logic and optical space, time and frequency division switching. These are mainly optical logic devices, optical switches, optical switching matrices, optical memories and optical wavelength multiplexers and demultiplexers and optical wavelength shifters. The devices are based on a variety of operating principles and are implemented with a variety of technologies. The basic principles and technologies are described together with typical performance parameters. The different devices and technologies are compared, and areas of possible improvements indicated. As an application of this survey, the possibility of implementing optical logic circuits and an optical time-division switch for Sonet based transmission systems is discussed. / Master of Science

The invention of the telephone and the telegraph opened the door to worldwide corrmunications. Over the years, complex and versatile corrmunication systems have evolved involving many devices and technologies. Switching protocols between switching offices have been established in accordance with the nature of the machines and with the capabilities of the transmission medium and its environment. Switching systems are now stored program oriented, providing a more generalized and digitally oriented internal switching capability. This report will discuss the Time Slot Interchange ( TSI), an important component of the Digital Central Office (DCO). The operation of the send section and the receive section and their relationship to the port group highways and cross office highways are presented in detail. The various TSI corrmands for performing the necessary operations are discussed. The TSI considered is that designed by Stromberg-Carlson, and future design trends in the design are presented.