Video Distribution System Research Articles

Fiber-optic digital video distribution system for using high-definition television signals using laser-diode optical switch

A fiber-optic high-definition television (HDTV) distribution system is discussed, which economically distributes HDTV signals to customers at a bit rate of about 100 Mb/s. The subscriber network is formed in a star topology to facilitate bidirectional connection. The distribution system uses digital video transmission at 1.3 mu m wavelength using single-mode fiber. The video channel selection is made by an optical video selector. The optical selector consists of laser diode optical switch modules, which have a gain in the 'ON' state and two-input, two-output 3 dB couplers. The authors describe the bit error rate characteristics of a signal-mode fiber digital distribution system using a four-input, one-output optical selector.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Configuration and Characteristics of a Fiber-Optic Video Distribution System

A multiservice fiber-optic subscriber system using wavelength division multiplexing technology has been developed by Nippon Telegraph and Telephone Corporation to provide both 64 kbits/s and broad-band communication services on a single multimode fiber. The subscriber network is formed in a star topology to facilitate bidirectional connection. The system was put in service in March, 1985, as part of the information network system (INS) model system. This paper describes the configuration and characteristics of the video distribution system of this fiber-optic subscriber system. The distribution system uses analog baseband video transmission at a 0.89μm wavelength. The video channel selection is made by an FDM video tuner installed in a central office. The overall performance successfully met design objectives.

Fiber Optic Transport Systems for Present and Future Local Networks

This paper describes fiber optic transport systems for present and future local networks. The present most important fiber optic system in a local network emerges as a broad-band video distribution system, because large-scale system introduction might be attained only for distributed video services. The system architecture and system parameters are presented. As for future integrated services, a highspeed digital transmission system and local network architecture are very important. The network architecture should be constructed to meet the demands for increased flexibility, capacity, reliability, and economy. Considering expected future demands and technologies, a new fiber optic local network architecture is proposed. The architecture's main features are the use of transmission processing nodes and a multilane-ring structure in subscriber transfer networks in combination with star-shaped subscriber access lines.

Direct broadcasting by satellite in the USA: Interim regulations and implications

Technological advances in satellite communications and changes in regulatory philosophy in the USA came together at the end of the 1970s to foster a new medium — direct broadcasting by satellite (DBS). DBS, similar to other new television distribution systems, holds the promise not only of serving the people who cannot be reached by conventional television systems, but also of offering diverse programming to existing television audiences. However, the potential problems raised by the FCC's interim DBS regulations might jeopardize the economic viability and the development of future DBS systems in the USA, and might affect the interests of DBS audiences.

Chapter 3: Television Captioning at the Clarke School for the Deaf

Television captioning is a daily operation at Clarke School for the Deaf. This paper contains the history of Clarke's early involvement in television captioning and explains the two different methods of captioning used. Our cable television distribution system is described, and the technical means of our captioning process and equipment is detailed.

Satellite Television and Cultural Replacement Among Canadian Eskimos

The application of a satellite television distribution system in Canadian Arctic native communities has precipitated a new form of electronic colonialism. As a test of its influence, the degree of traditional culture replacement among Eskimo adults and their adolescent offspring in a television community was examined after two and one-half years of exposure to regular C.B.C. programming. "Television town" adult and adolescent responses were also compared with those generated by a group of high school students from media-isolated settlements. The results demonstrated significantly varied acculturation levels among the samples, with the greatest shift toward Euro-Canadian structures accruing to television town adolescents, followed by settlement students. Adults tended to be more attached to traditional norms. The prognosis extended is that the cultural replacement gap between adults and adolescents will increase with sustained exposure to southern television.

Conceptual Design of a Switched Television-Distribution System Using Optical-Fiber Waveguides

A conceptual design of a switched television-distribution system based on analogue intensty-modulated (IM) transmission through optical-fiber waveguides is discussed. Transmission of two TV channels and provision of telephone or data service over two optical-fiber waveguides to each subscriber by frequency-division multiplexing is considered first and then other design options such as spatial-division multiplexing, inclusion of copperwire pairsfor the supply of electrical power and telephone or data service is reviewed. Thepresent state ofdevelopment of system components is also discussed and areas requiring further development are pointed out. Theoretical Calculation of the possible transmission distances for analogue IM transmission of baseband and frequency-division multiplexed video signals is described. The results show that if-3 dBm (0.5 mW) of optical power modulated by a baseband video signal to a peak modulationfactor of 80% is launched into an optical-fiber waveguide, a distance of approximately 15 km can be spanned without a repeater. It is concluded that in view ofthe distances that can be covered by low-loss optical-fiber transmission systems, a centrally switched optical television distribution system may well be attractive for applications not only to urban areas, but also to rural areas. It is further suggested that an economic analysis is needed to ascertain the practicality of such a system.

The design of large-scale networks

The application of computer techniques to difficult large-scale network problems is discussed. The physical characteristics of two types of systems are described--computer-communication networks and cable television distribution systems. Two fundamental algorithms are presented, and applications to routing, reliability, and design of computer networks are given. The detailed engineering decisions that can be made by computer in the design of practical large-scale networks are illustrated by example for cable television systems. These examples are chosen to indicate the richness and difficulty of the problem of applying computers to network design.

VHF and UHF Television Receiving Equipment

This paper covers a study of various types of VHF and UHF television receiving equipment made by TASO Panel 2 and reported October 3, 1958. Information and performance data are given for antennas, transmission lines and television receivers. RF amplifier and oscillator electron devices (tubes and semiconductors) used in television tuners for both VHF and UHF are discussed and tables showing relative performance data for devices of various types are included. In addition to this study of home television receiving equipment, TASO Panel 2 made studies of 1) community television antenna and distribution systems, and 2) the effects of transmitter sound power reduction on television receiver performance. Results of these studies are also included. In general, data collected by Panel 2 show that performance of VHF equipment is markedly superior to that of UHF equipment and that a reduction in sound power of television transmitters is harmful to television reception, particularly in fringe areas.

Developments in closed-circuit television

With the introduction of the flexible multichannel television distribution system and the 2-way television system, it is now possible to simultaneously transmit and receive signals at a number of pickup-reception points in the system. The operation of these two systems are explained for those installed at Fort Monmouth and Case Institute of Technology.

Local wire television networks

A new local video distribution system has been developed which provides equalization and amplification of signals transmitted over links between television studios, transmitters, coaxial cables, and microwave networks. The equipment consists of a transmitting terminal, an intermediate repeater with cable equalizers, and a receiving terminal.