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Showing papers on "High-bit-rate digital subscriber line published in 1979"


Journal ArticleDOI
TL;DR: A new subscriber communication system and its design philosophy are described, which utilizes the existing subscriber line efficiently and is entirely suitable for coming telephone and data public digital network.
Abstract: A new subscriber communication system and its design philosophy are described. In addition to telephone communication, the system is simultaneously able to offer data communication, still picture communication, etc. The system is composed of a packetized voice/data terminal, a multi-service switching equipment and the digital subscriber loop connecting between them. The system utilizes the existing subscriber line efficiently and is entirely suitable for coming telephone and data public digital network. 64 kbit/s PCM coded voice conversation and 48 kbit/s data communication were achieved simultaneously over 96 kbit/s digital subscriber line which was spanned up to 2 km.

17 citations


Journal ArticleDOI
TL;DR: The Electronics Research Laboratory at the Norwegian Institute of Technology has since 1974 studied PCM-transmission in the local subscriber plant with choice of design parameters and concept for a digital subscriber set.
Abstract: The Electronics Research Laboratory at the Norwegian Institute of Technology has since 1974 studied PCM-transmission in the local subscriber plant. A short discussion of this work is presented together with choice of design parameters and concept for a digital subscriber set. Construction and laboratory testing of the digital subscriber set are described. The paper concludes with a discussion on future development.

12 citations


Patent
30 Aug 1979
TL;DR: In this paper, the analog circuit portions which are associated with a sub-group of a subscriber line and circuit for coding and decoding are combined into sub-modules such as printed circuit boards which are mounted on a common carrier plate at a spacing from the main portion of the plate so that the carrier plate forms the circuit carrier for the paths and components of the digital component of the circuits.
Abstract: Subscriber circuits used for connecting analog operated subscriber line to digital switching networks have analog circuit portions which are individually associated with the individual subscriber lines and also have circuits for coding and decoding signals. Digital control and interface circuits are commonly associated with a plurality of such subscriber circuits and in the present invention the analog circuit portions which are associated with a sub-group of a subscriber line and circuit for coding and decoding are combined into sub-modules such as printed circuit boards which are mounted on a common carrier plate at a spacing from the main portion of the plate so that the carrier plate forms the circuit carrier for the paths and components of the digital portion of the circuits.

3 citations


Patent
25 Apr 1979
TL;DR: In this article, a single-sideband transmission (SST) system employing single-carrier transmission with single-input single-out (SISO) was proposed to maximize the available frequency spectrum without requiring individual stable subscriber carrier sources by utilizing a common source signal for all subscriber carriers.
Abstract: A station carrier telephone system employing single sideband transmission permits optimal utilization of the available frequency spectrum without requiring individual stable subscriber carrier sources by utilizing a common source signal for all subscriber carriers. The common source signal is received via the common transmission line at each subscriber circuit where it is processed and mixed with the similarly received central office carrier to derive a difference frequency signal which serves as the subscriber carrier. In a preferred embodiment sixteen channels share the common transmission line and employ sixteen adjacent subscriber frequency bands and sixteen adjacent central office frequency bands.

1 citations


Journal ArticleDOI
TL;DR: A graphic method for the analysis of opto-electronic digital transmission lines is described, using as a criterion the cost per bit/second per kilometer of wire, denoted "CSP".
Abstract: The efficiencies of different methods for subscriber-loop digital transmission are compared, using as a criterion the cost per bit/second per kilometer of wire, denoted "CSP". Approaches to reduction of CSP are suggested, in particular the use of opto-electronic transmitters and receivers in a differential connection, resulting in a relatively noise-immune subscriber line. A graphic method for the analysis of opto-electronic digital transmission lines is described.

1 citations