Telephone networks are offering an increasingly wide range of advanced services such as free-phone numbers, call waiting, virtual private networks, and so on. In order to aid the rapid introduction of such services, t...
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Telephone networks are offering an increasingly wide range of advanced services such as free-phone numbers, call waiting, virtual private networks, and so on. In order to aid the rapid introduction of such services, the telecommunications industry has been working on a standardized architecture which will allow services to be specified as software and loaded onto a flexible network. This architecture has become known generically as the intelligent network. In this paper, a brief overview of the history, current status, and future direction of advanced telecommunication services implemented through intelligent networks is provided, in particular considering mobile issues.
Software development efforts are characterized by;project failures, runaway projects and integration and communication problems. Analyzing why some projects finish on target while others lose track of their original o...
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Software development efforts are characterized by;project failures, runaway projects and integration and communication problems. Analyzing why some projects finish on target while others lose track of their original objectives, constraints and milestones, can only be viewed as a long term investment. The study of failures is a sensible approach for utilizing past experience and advancing to the next level of maturity. This paper introduces the discipline of Forensic Engineering and frames it within the ECBS environment. The value of failure analysis is discussed from a number of viewpoints. This paper calls for a new attitude towards failure, where in order to maximize potential learning, acceptance of failure is the new order of the day.
The advent of complex computer-based systems require the development of an effective training module that will enable systems engineers and designers to grasp the basic principles that govern the operation and structu...
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The advent of complex computer-based systems require the development of an effective training module that will enable systems engineers and designers to grasp the basic principles that govern the operation and structure of such systems. This module must be capable of highlighting the shortcomings of present engineering practices and how these shortcomings can be compensated for. It must also identify core problems that will lead further research. In addition, the module must be capable of encapsulating the extracted knowledge from forensic studies to make full use of detailed analyses and resultant knowledge.
The discussion on future digital TV services puts some requirements on the design of the next generation of TV receivers. For quite some transition period they must be able to receive both (Analogue as well as digital...
The discussion on future digital TV services puts some requirements on the design of the next generation of TV receivers. For quite some transition period they must be able to receive both (Analogue as well as digital services).
We aim at modeling conditional access in any television environment (terrestrial broadcasting, cable and satellite). After defining the subject by saying what conditional access is, two models are presented. They corr...
We aim at modeling conditional access in any television environment (terrestrial broadcasting, cable and satellite). After defining the subject by saying what conditional access is, two models are presented. They correspond to two different systems, wide-spread in Europe: — The first model distributes control words. It is illustrated by “Discret 1”, a proprietary system used by about 3 500 000 subscribers of Canal-Plus in France. — The second model distributes authorizations. It is illustrated by “Eurocrypt”, an open system used by about 800 000 receivers throughout Europe: Filmnet and Kinnevik (600 000), Canal-Plus (60 000), France Telecom (50 000), Polycom, Maxat, KabelKanal,… — The emergence of digital signals technically facilitates the design of open systems. The use of a strong cryptography becomes justified. The encipherment techniques appear at three different levels: — for scrambling the program components, — for controlling the access rights, — for managing the access rights and for updating the authorization keys. — This modelisation emphasizes the impact of standardization and the reserves for further evolution. The knowledge harvested on existing systems allows to determine the axes for additional developments, specifically in relation with digital television.
The United States Federal Communications Commission (FCC) is the governmental body charged with regulating the terrestrial broadcasting industry. In July of 1987, in response to a petition from broadcasters, the FCC i...
The United States Federal Communications Commission (FCC) is the governmental body charged with regulating the terrestrial broadcasting industry. In July of 1987, in response to a petition from broadcasters, the FCC issued a Notice of Inquiry (NOI) concerning the adoption of standards that would permit an advanced television service to be established in the United States. 1 After studying the response to the NOI, the FCC, in September 1988, issued a Tentative Decision and Further NOI 2 defining a plan of action. This plan of action was further defined by FCC Chairman Sikes on 21 March 1990. 3 In summary, the tentative decision and plan of action requires that: (1) Existing terrestrial broadcasters must be able to implement an advanced television service; (2) The spectrum for such service will be found within the existing VHF and UHF bands; (3) ATS broadcasting shall be received by the present population of over 160,000,000 NTSC receivers by an ATS signal which is accompanied by a simulcast of an NTSC signal. (4) Channel bandwidth is limited to 6 MHz.
One of the goals in the current European work on digital television broadcasting is to achieve as much commonality as is practicable between system specifications for terrestrial, satellite and cable applications. It ...
One of the goals in the current European work on digital television broadcasting is to achieve as much commonality as is practicable between system specifications for terrestrial, satellite and cable applications. It is already generally accepted that the MPEG-2 standard should provide the basis for common source coding across these applications. Modulation and channel coding, on the other hand, are likely to be application specific because of the very different properties of terrestrial, satellite and cable channels. Lying somewhere in the middle is the area of multiplexing. The prospect for a common approach to multiplexing across different media, and indeed between different regions of the world, has excited widespread interest. But what exactly is multiplexing, what features would a common system need to deliver to broadcasters and consumers, and is a common approach to multiplexing feasible?
Color television systems have always assumed a specific display with the color coding in the camera and transmission system derived from this display using the CIE system of colorimetric specification. However, displa...
Color television systems have always assumed a specific display with the color coding in the camera and transmission system derived from this display using the CIE system of colorimetric specification. However, display phosphors have changed since the beginnings of color television resulting in increased display luminance but at the expense of significantly reduced color gamut that can be displayed. Since camera characteristics have changed to be compatible with current CRT displays, the color gamut that is captured and transmitted is limited to that of current CRT displays. We will likely see new display technologies in the future and these displays may well be capable of displaying a larger color gamut than current CRT's. Also other imaging systems, such as film, have color gamuts larger than current CRT's, so interoperability with other imaging systems demands a larger color gamut. For future television we need to define a source coding colorimetry that satisfies our long term need for a larger color gamut. We than perform color transformations at system interfaces and in some displays to derive the signals appropriate for that specific system or display. Two approaches for capturing a larger color gamut are considered. The second approach, allowing negative and above white RGB signals, seems to be the most readily implemented with current technology and is being evaluated for inclusion into the production standards for future television systems.
A digital transmission broadcasting system must be able 10 control degradation of the received picture due to transmission errors. Error correcting algorithms are one of the most powerful technologies, but the many ot...
A digital transmission broadcasting system must be able 10 control degradation of the received picture due to transmission errors. Error correcting algorithms are one of the most powerful technologies, but the many other technologies for error control should also not be forgotten. A total approach to error management must be applied when designing a digital terrestrial television broadcasting system. Other important technologies include error detection and concealment methods, transmission equalization technologies, modulation systems, including coded modulation, and weighted error protection systems.
This paper discusses modulation and channel coding issues related to digital television terrestrial broadcasting (DTTB), such as data throughput, spectrum efficiency, single- and multi-carrier modulations, interferenc...
This paper discusses modulation and channel coding issues related to digital television terrestrial broadcasting (DTTB), such as data throughput, spectrum efficiency, single- and multi-carrier modulations, interferences under simulcasting conditions and multi-layer services.
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